Absolute Science: Year 8 Non-specialist Teacher's Pack

Contents

Introduction 2

1 Atoms and elements 42 Light 363 Food and digestion 864 Compounds and mixtures 1305 Respiration 1646 Sound and hearing 2027 Microbes and disease 2468 Heating and cooling 2889 Rocks and weathering 33810 The rock cycle 37611 Ecological relationships 41612 Magnets and electromagnets 456

End of Unit test mark record 487Technician notes 489Framework matching chart 505

Year 8 Complete Teacher Pack CD-ROM

Brian Arnold • Geoff Jones • Mary Jones • Emma Poole

YOU MAY BE ABLE

TO DO

WORKSHEET A1,‘DENSITY OF A

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Absolute Science has been written to support the new Framework for TeachingScience Years 7, 8 and 9 and fits exactly to the format of the Key Stage 3 Schemeof Work from QCA.

The Pupil Books and Teacher Packs can be used in conjunction with each other oras stand-alone teaching tools, to deliver fully the National Curriculum statutoryorders and implement the Framework for Teaching Science Years 7, 8 and 9.

Each chapter in the Pupil Book contains:• A real-world example at the beginning of each chapter to give pupils a context

for the theory they are about to learn• Science content which matches the Scheme of Work• Questions interspersed throughout the text to reinforce and consolidate learning

are denoted by this icon.

• ‘Think about’ questions for group or whole class discussion are denoted by thisicon.

• Investigation activities contained on Worksheets in this Teacher Pack which areflagged by this icon.This gives pupils an exact reference for where the investigation fits in with thetheory, but also gives the teacher the flexibility of deciding whether to carryout the investigation or not.

• A literacy activity at the end of each chapter denoted by this icon. • A summary of Key ideas and Key words at the end of each chapter• A section of differentiated End of chapter questions

Absolute Science has two Teacher Packs per year. One is for specialist, experiencedScience teachers, and one is for non-specialist Science teachers and newly qualifiedteachers. The Non-specialist Teacher Pack is also ideal for cover lessons.

Both Teacher Packs contain:• Starting points, detailing what pupils should already know from their Key Stage

2 studies and Year 7 studies• A Language for learning checklist which denotes all language to be introduced

within the chapter• A Learning checklist denoting the key concepts pupils should be taught within

the chapter• Links to other Units in the Key Stage 2 Scheme of Work and the Key Stage 3

Scheme of Work• Suggestions for Cross-curricular links, and Literacy, Numeracy and ICT activities• Learning outcomes for each chapter at three different levels• A Topic list for each chapter and accompanying teacher notes• Programme of Study references

Introduction

2

Pupil Book

Specialist and Non-specialist Teacher Packs

3

Absolute Scheme of Work Scheme of Work Unit titleScience UnitChapter

3 8A Food and digestion5 8B Respiration7 8C Microbes and disease

11 8D Ecological relationships1 8E Atoms and elements4 8F Compounds and mixtures9 8G Rocks and weathering

10 8H The rock cycle8 8I Heating and cooling

12 8J Magnets and electromagnets2 8K Light6 8L Sound and hearing

Log on to www.CollinsEducation.com/absolutescience/ to see:• Web-links for each chapter for Year 7 material• Extra teaching notes and worksheets to supplement the printed resources• Regularly updated Science Summaries which provide a digest of Science in the

news• The free teacher notes for the Absolute Science Key Stage 2–Key Stage 3

Transition Project• Updated material arising from advances in Science or curriculum developments

Introduction

Absolute Science and the QCA Scheme of Work

The Absolute Science Website

• A learning checklist for pupils• An overarching Lesson plan denoting lesson focus, expectations for the lesson

at three different levels, together with a list of resources for each lesson• Practical and non-practical worksheets. All worksheets can be used with the

whole class since questions on each worksheet are matched to the three levelsof learning outcome as denoted on the overarching Lesson plan. Therefore,more able pupils will be able to complete all questions, whereas less ablepupils should only be expected to answer the ‘core’ questions

• A differentiated End of Unit test with exemplar mark scheme denotingsuggested levels

• Answers to all Pupil Book and worksheet questions• An End of Unit test mark record sheet• A summary of the Technician notes for each lesson• Framework matching charts

In addition, the Non-specialist Teacher Pack contains:• Teaching hints and tips for each chapter• Detailed lesson plans containing starter activities and plenaries, together with

homework suggestions

All material contained in the Non-specialist Teacher Pack is contained on a fullycustomisable CD-ROM giving the teacher full flexibility in the use of AbsoluteScience.

Pupils should be familiar with the following ideas:• The differences between solids, liquids and gases• Have seen and described changes of state• Know how models can be used to explain phenomena

1 Atoms and elements

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Starting points

Language for learning

AtomChemical reactionCompoundElement

FormulaGasLiquidMaterial

ModelMoleculeParticle

Periodic tableof elements

SolidSymbol

In this topic pupils should learn:• the names of a wide range of materials• that there are a small number of elements from which all other substances are

made• the names of some elements, and be able to use symbols to represent these

elements• that elements can be classified as metals or non-metals• the characteristic properties of metals and of non-metals• that the atoms of two or more elements can be joined together during chemical

reactions to form compounds• how to make a metal oxide• how to write a word equation to represent a chemical reaction• how compounds can be represented using formulas

Learning checklist

Links

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Links with other Units in the Key Stage 3 Scheme of Work

Unit Title

7G Particle Model of Solids, Liquids and Gases7H Solutions8F Compounds and Mixtures9E Reaction of Metals and Metal Compounds9F Patterns of Reactivity

© HarperCollins Publishers Ltd 2003 Absolute Science Year 8

CH A P T E R

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Cross-curricular linksThe historical impact of ideas about atoms is covered in Unit 21 ScientificDiscoveries.

LiteracyThere is a literacy activity on Antoine Lavoisier in the Pupil Book.


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Most pupils

Scientific enquiry• Select information about elements and their properties from a range of secondary

sources• Describe how to deal with hazards when preparing oxides• Identify an approach to finding out whether a material is an element or not• Explain how their results provide appropriate evidenceMaterials and their properties• Recognise that there are a small number of elements and name some of these• Explain that compounds are made when atoms of different elements join

together• Use symbols for elements and to represent reactions in word equations

Pupils who have not made so much progress

Scientific enquiry• Find information from selected sources about elements and their properties• Describe some hazards in preparing oxides and describe the results of their

investigationsMaterials and their properties• Name some elements and represent these by symbols• Distinguish between symbols for elements and formulas for compounds• Name a wide variety of materials

Pupils who have progressed further

Scientific enquiry• Find information from selected secondary sources about elements and their

properties• Identify limitations of evidence obtained about whether a substance is an

element or notMaterials and their properties• Identify elements whose properties do not fit the general pattern of metals and

non-metals• Begin to represent compounds by formulas

Learning outcomes


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Topic list and teaching notes

Atoms, elements and compoundsThe Pupil Book introduces this topic using illustrations of a range of materials.Pupils may also be provided with samples of these or other materials to handle.

Safety: If hazardous elements are used they must be safely sealed insidecontainers, and pupils should be reminded of the hazards associated withthem. They will have studied these hazards in Pupil Book 1 (Year 7),Chapter 1.

It is suggested that pupils be asked to name the materials that make up acollection of objects. Help the pupils to appreciate the huge range of substanceswhich exists. Pupils should then be encouraged to define the term ‘element’,incorporating the idea that elements are the materials from which everything ismade. Help them to divide the materials into elements and other materials.

Pupils could be asked to think of the names of some other elements, and mayhave time to complete Worksheet A1, Elements wordsearch. Help pupils toappreciate that there are only about 100 elements, but that they can be madeinto millions of other materials.

Atom modelIn this section, the class uses the Pupil Book to explore a model for representingatoms. Pupils should know that atoms are very small particles and should behelped to use the model to appreciate that in this model:

• bricks represent atoms• elements are made of just one type of atom (colour of brick)• atoms of different elements (different coloured bricks) can be joined together

to form an enormous variety of materials.

Pupils may then be asked to complete the questions in the Pupil Book.

SymbolsPupils should learn about the system of chemical symbols that can be used torepresent elements. This is developed on Pupil Book page 7. Pupils may find theChapter 1 Information sheet, Elements and symbols, useful when answeringquestions, and may also attempt Worksheet A2, All about platinum, which willhelp pupils to familiarise themselves with a number of symbols.

The properties of elementsThis section will need two lessons to cover the material thoroughly.

Pupils in groups can investigate the properties of a selection of the hundred or soknown elements, so that the class as a whole covers them all. Groups will requireaccess to a variety of secondary sources, such as data books, CD-ROMs and theinternet, in order to complete a copy of Worksheet A3, Properties of elements, foreach element. Then show the class a periodic table or refer them to the one onPupil Book page 9. Ask groups to arrange their element sheets in the samepositions as the elements are placed in the periodic table. Pupils shouldappreciate how similar elements are grouped together. The class can then beasked to complete this section’s questions in the Pupil Book, or they may be giventhe opportunity to carry out the activity on Worksheet A4, Properties of elementsin the periodic table.

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As an extension activity, pupils could find out about the history and uses of aparticular element. This material could be collated to form a class display.

How do we get new materials?Pupils should be reminded of the terms ‘atoms’, ‘elements’ and ‘compounds’,and introduced to the term ‘molecules’ using the Pupil Book, which provides theopportunity to describe the atoms present in a number of simple molecules.

Following safety precautions and procedures (in QCA KS3 Scheme of WorkUnit 8E), demonstrate a number of chemical reactions with the formationof new compounds. For each reaction, pupils should record the appearanceof the reactants and products. They should be helped to appreciate thatthe changes in appearance that they have noted are evidence that achemical reaction has taken place.

Pupils will need to practise the names of compounds verbally and in writing, forexample, chlorine forms chloride compounds. To this end, the class can be askedto complete Worksheet A5, Naming new compounds.

Making metal oxidesIn this section, pupils have the opportunity to extend their experience by carryingout a number of simple reactions in Practical activity: Making metal oxides(Lesson 6). Pupils should be given small samples of copper, zinc and magnesiumto heat to ignition.

Safety: Warn pupils of all safety precautions they should take, includingnot to look directly at the magnesium when it is being burnt.

Ask pupils to record the appearance of the materials before and after heating:they should note a change in appearance and then try to name the newcompounds they have formed.

Pupils may also try to write word equations for the reactions. The Pupil Bookprovides assistance with this. Some pupils will need to be reminded that oxygenforms oxide compounds. Formula equations may be discussed as an extensionactivity with some pupils.


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Atoms, elements and compoundsSome pupils may find it very difficult to differentiate between the various objectsshown at the start of the chapter, and the materials from which these objects aremade, and those pupils will need some help.

Many pupils do not realise that gases are materials, so try to include some gasesin the selection of different materials that you show to pupils. Gas jars filled withair and an appropriate label could give a quick and cheap example.

Atom model; symbols

Some pupils may find that there are limitations to the bricks model ofrepresenting atoms. The advantages and disadvantages of the model could bediscussed with these pupils.

Teaching hints and tips

8 © HarperCollins Publishers Ltd 2003 Absolute Science Year 8

When explaining the symbols used to represent elements, emphasise that whenevertwo letters are used as a symbol, the first letter must be a capital and the secondletter must be lower case.

Worksheet A3, Properties of elementsSome pupils may need help in selecting the key properties that they are searchingfor from the vast amount of information available about different elements.

Atoms joined togetherSome pupils may benefit from making models to represent the simple moleculesdiscussed in this section.

Programme of study references

Sc1

Scientific Enquiry

1a, 1b, 1c, 2b

Sc2

Life Processes andLiving Things

Sc3

Materials andTheir Properties

1a, 1b, 1c, 1d, 1e,1f, 3a

Sc4

Physical Processes

9© HarperCollins Publishers Ltd 2003 Absolute Science Year 8

What I have learnt

Atoms and elements

When you know what these words mean, tick the box!

Gas

Symbol

Atom

Material

Solid

Compound

Chemical reaction

Periodic table

of elements

Liquid

Model

Particle

Formula

Element

Molecule

Tick the one you feel happiest with!

• I know the names of a lot ofmaterials

• I know that there are a small numberof elements from which othersubstances are made

• I know the names of some elements• I can use symbols to represent some

elements• I know that elements are metals or

non-metals• I know the properties of metals and

non-metals• I know that atoms of two or more

elements can be joined together toform compounds

• I know how to make a metal oxidesafely

• I can write a word equation to showa chemical reaction

• I know that compounds can berepresented by formulas

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I need somemore help

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CHECKLIST

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Absolute Science Lesson Plan

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Date Class Mixed Ability/Set Room Time 50 mins

Lesson Focus Pupil Book 2 p. 4Materials

Expectations

Most Pupils Appreciate that there is an enormous range of materials which aremade from a limited number of elements.

Less Able Pupils Know that there is an enormous range of materials in the worldaround them.

More Able Pupils All the above, plus can distinguish between materials made fromelements and materials made from compounds.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Using names of materials and elements.Numeracy:ICT:

Cross-curricular developmentPupils may have experience of using a range of materials in technology lessons.

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Equipment & resources needed

Demo: Objects made from differentmaterialsA selection of elements and compounds,e.g. silver ring, aluminium foil, graphitesticks, gas jar containing oxygen, woodenruler, plastic ruler, plant

Worksheet A1 Elements wordsearchOne sheet per pupil (paper exercise)

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Timing Teaching and Learning Activities Differentiation Learning Outcomes

10 In and register. Less able pupils will need more help to identify Pupils are able to name the materials from which a range of Starter. Use Q and A to draw out pupils’ previous knowledge about particles. the materials. illustrated objects are made.Instruct them to consider the photographs of different objects on Pupil Book page 6. Ask pupils to identify the objects and the materials from which they are made.

10 Development. Set out the demo on objects made from different materials. Pupils have experience of handling a range of materials and Ask the pupils to split them into two groups: can divide these materials into elements and compounds.– elements (made of just one type of atom),– compounds (made of two or more different types of atom joined together).

20 Refer to Pupil Book page 4. Explain the terms ‘element’ and ‘compound’, More able pupils will be familiar with the names Pupils know that elements are made of only one type of atom and help pupils to write a definition for each. of many elements, while less able pupils may and that compounds are made of two or more types of atom. Distribute Worksheet A1 Elements wordsearch, and direct pupils to start need help to recall these names. Pupils become familiar with the names of some of the work on it. elements.

10 Plenary. Select three objects to use in this review. Ask pupils to name each Pupils are familiar with a range of materials and can explain object and then to name the material from which it is made. Finally, ask pupils the differences between elements and compounds.to state whether each object is made from an element or from a compound.

Homework: Complete Worksheet A1.

Chapter 1 Lesson 1 – Detailed Lesson Plan

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Lesson Focus Pupil Book 2 pp. 5–8Elements, their names and symbolsCompounds

Expectations

Most Pupils Can use a model to represent atoms, elements and compounds.Use symbols to represent elements.

Less Able Pupils Know that materials are made of very small particles called atoms.Know that elements can be represented by symbols and arefamiliar with the symbols used for a small number of elements.

More Able Pupils All the above, plus are familiar with a range of elements and theirsymbols.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Using names of elements.Numeracy:ICT:

Cross-curricular development

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Demo: Atom modelLego®, or other bricks that can be joinedtogether, in several different colours

Worksheet A2 All about platinumOne sheet per pupil (for homework)

Chapter 1 Information sheet: Elementsand symbolsOne sheet per pupil (needed to completeactivities in Pupil Book)

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5 In and register. Pupils reinforce the definition for elements.Starter. Use Q and A to remind pupils of the definition for elements and of some of the elements discussed in Lesson 1.

15 Development. For the demo of an atom model, see Pupil Book page 5 and Some pupils who are kinaesthetic learners may Pupils understand how atoms can be represented by bricks the bricks to introduce the atom model. benefit from handling the bricks and equating and can explain elements and compounds using the model.Instruct pupils to answer questions 1 to 3 on Pupil Book page 6, recording them to parts of the atom model described in the answers in their workbooks. Pupil Book.

20 Use the Pupil Book to explain how elements can be represented using symbols. Less able pupils will need more help to complete Pupils use symbols to represent different elements.Distribute Chapter 1 Information sheet: Elements and symbols, and instruct these questions.pupils to complete questions 4 to 6.

10 Plenary. Use a quiz format to define atoms, elements and compounds, to Pupils review the main themes of the lesson.identify some elements from their symbols, and to identify some symbols from the elements’ full names.



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Lesson Focus Pupil Book 2 pp. 8–9Investigating elements (2 lessons)

Expectations

Most Pupils Know that elements are arranged into a periodic table so thatelements with similar properties are grouped together.

Less Able Pupils Know that there are about 100 elements that have differentproperties.

More Able Pupils All the above, plus begin to become familiar with some parts ofthe periodic table and the properties of elements found in thoseareas.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Reading information from secondary sources and completion of

data sheets for different elements.Numeracy: Use of internet and CD-ROMs to investigate different elements.ICT:


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Worksheet A3 Properties of elementsGroup, then class, activityAbout 16 sheets, cut up to complete forelements 1 to 89Table about 75 cm x 100 cm on which toarrange elements as in the periodic tableAccess to data books, CD-ROMs and theinternet

Worksheet A4 Properties of elementsin the periodic tableOne sheet per pupil (paper exercise)

Mendeleev’s organisation of theelementsVideo clip: Channel 4 Learning ‘BigQuestions: The Nature of ScientificEnquiry’, ISBN 186215758-8, Track 4Mendeleev’s dream

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10 In and register. Pupils recall the atom model.Starter. Remind pupils of the atom model discussed in Lesson 2 and inform pupilsthat they will be investigating the properties of many of the 100 known elements.

30 Development. Divide pupils into groups of 3 or 4, and distribute the required Less able pupils may need more help to complete Pupils have experience of using secondary sources to research number of Worksheet A3 Properties of elements to each group (total 89, the information sheets. Less computer literate the properties of different elements. Pupils realise that to actinium) and then allocate the elements between the groups. Instruct pupils pupils may need help to access information. different elements can have very different properties.to complete one sheet for each of their elements using data books, CD-ROMs and/or the internet.

10 If available, show the video clip on how Mendeleev organised the elements Pupils are aware of the work of Mendeleev.in his periodic table.

20 Direct group representatives to place the elements information sheets in periodic Pupils use their research to arrange the elements and note table order. trends in the periodic table. Discuss the trends shown, for example, ask pupils to identify where the metals, non-metals, solids, liquids, gases and magnetic elements are found.

20 Instruct pupils to record the class results using Worksheet A4 Properties of Less able pupils will need more help to Pupils record the results of their research.elements in the periodic table. complete this sheet.

10 Instruct pupils to answer questions 7 to 10 on page 9 of the Pupil Book. Pupils review the main themes of lesson and appreciate the Plenary. Through Q and A, guide pupils to an appreciation of the usefulness of usefulness of the periodic table.the periodic table in grouping elements with common properties.

Homework: Find out about the history and uses of a particular element. (This information can be collated to form a class display.)

Chapter 1 Lesson 3/4 – Detailed Lesson Plan

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Lesson Focus Pupil Book 2 pp. 9–13New compounds from chemical reactions

Expectations

Most Pupils Can name new compounds.

Less Able Pupils Know that atoms of elements can be joined together to makecompounds.

More Able Pupils All the above, plus can use formulas to describe the elementspresent in simple molecules.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Writing the names of new compounds.Numeracy: Using formulas to describe simple molecules.ICT:


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Demo: Chemical reactions formingnew compounds• Hydrogen + oxygen � waterHydrogen balloon• Sodium + chlorine � sodiumchlorideSand, sodium, crucible lid, gas jarcontaining chlorine• Carbon + oxygen � carbon dioxideToast to burn• Copper + sulfur � copper sulfideCopper, sulfur, borosilicate, boiling tube,mineral wool

Worksheet A5 Naming newcompoundsOne sheet per pupil (for homework)

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10 In and register. Pupils recall that the 100 elements can be joined together to Starter. Remind pupils that there are only about 100 elements, but that these form an enormous number of new compounds.elements can be joined together to form an enormous number of new compounds.

10 Development. Use the Pupil Book page 10 to explain how the atoms are arranged Less able pupils will need help to complete the Pupils can describe the atoms present in a number of simple in a selection of simple molecules. table, and may benefit from using the bricks molecules.Instruct pupils to complete question 11 on page 11 of the Pupil Book. employed in the atom model demo of Lesson 2.

10 With the class, run through the chemical reactions on Pupil Book pages 12–13. Less able pupils may need more help to name Pupils can name new compounds.Then, taking and pointing out safety precautions to the class, demonstrate the new compounds. More able pupils can be formation of new compounds. introduced to symbol equations.Explain how the new compounds are named and that the chemical reactions can be represented by word equations.

10 Distribute Worksheet A5 Naming new compounds and instruct pupils to Remind less able pupils about naming new Pupils have practice in naming new compounds.complete the questions. compounds, e.g. oxygen forms oxide compounds.

10 Plenary. Use Q and A to ask pupils to name the new compounds formed when Pupils can apply their knowledge of reactions and formation iron reacts with sulfur and magnesium reacts with oxygen. Ask pupils to write of compounds to unfamiliar situations.a word equation to represent these reactions.Give the formula for glucose, C6H12O6. Ask pupils to give the names of the different elements in the compound glucose, and the relative number of each type of atom present.



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Lesson Focus Pupil Book 2 pp. 13–14Making metal oxides

Expectations

Most Pupils Can describe the burning of metals to form metal oxides usingword equations.

Less Able Pupils Know that metals can be burnt to form metal oxides, and carry outthese reactions safely.

More Able Pupils All the above, plus can use formula/word equations to representreactions.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Naming new compounds, recording the appearance of their metals and metal oxidesNumeracy: Use of formula equations. ICT:


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Practical activity: Making metal oxides Per group:Small pieces of magnesium, zinc andcopper to burnBunsenTongsSafety mat Per pupil:Goggles

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10 In and register Pupils know that new compounds are made during chemical Starter. Through Q and A, elicit from pupils that new compounds can be made reactions.by chemical reactions.

25 Development. Explain to pupils that they will be carrying out three chemical Less confident pupils may need help to carry out Pupils have experience of carrying out a series of chemical reactions. Show them how to set up the equipment and explain how, when a these reactions and record observations. reactions safely. Pupils appreciate that new compounds can metal burns it reacts with the oxygen present in the air to form a metal oxide. have very different properties from the elements from which Instruct pupils to carry out the three reactions in the practical activity: they were formed.Making metal oxides. They should draw up a table in their workbooks and record for each reaction: the appearance of the metal before the reaction and the appearance of the metal oxide after the reaction.

10 Plenary. Use Pupil Book pages 13–14 to review the pupils’ reactions and their Less able pupils may benefit from using the Lego® Pupils consolidate their understanding of the reactions they observations, and formula/symbol equations. Remind pupils that oxygen forms bricks from the atom model to represent their have carried out and of the new compounds they have made.oxide compounds. reactions. More able pupils can use formula/

symbol equations.

5 Extension. Instruct pupils to complete questions 12 and 13 on page 14 of the More able pupils can be asked to write symbol Pupils can apply their knowledge to unfamiliar situations.Pupil Book. equations.

Homework: Complete any unfinished questions from Chapter 1.


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Lesson Focus Pupil Book 2 Chapter 1Revision and consolidation of Chapter 1

Expectations

Most Pupils Have an understanding of models, symbols and formulas used torepresent atoms, elements and compounds.

Less Able Pupils Have a basic understanding of the topic.

More Able Pupils All the above, plus are fluent in all aspects of the topic using a fullrange of subject-specific vocabulary.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Identifying and explaining the key words. Literacy activity on Lavoisier.Numeracy:ICT:


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End of Unit testOne set of sheets per pupil

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20 In and register. Pupils have a record of the main ideas of the topic.Starter. Remind the class of the main ideas in Chapter 1. Direct pupils to read Pupils gain an understanding of earlier ideas of scientificthe Literacy activity on Antoine Lavoisier, Pupil Book page 15, then to answer inquiry, and extend their subject-specific vocabularythe questions in their workbooks.

30 Pupils sit in appropriate places and carry out the End of Unit test. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the correctly and will attempt the extension questions. End of Unit test.

Homework: Complete the Literacy activity.


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The names of twenty elements have been hidden in the wordsearch below.When you find the name of an element, circle it, then add its name to thelist below. One has been done for you.

Element

1 ................................... 2 ...................................

3 ................................... 4 ...................................

5 ................................... 6 ...................................

7 ................................... 8 ...................................

9 ................................... 10 ...................................

11 ................................... 12 ...................................

13 ................................... 14 ...................................

15 ................................... 16 ...................................

17 ................................... 18 ...................................

19 ................................... 20 ...................................

A1 Elements wordsearchCHAPTER

WORKSHEET1

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oxygen

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A2 All about platinumCHAPTER

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The passage below has been written using a code.

Rewrite the passage, but every time you see the name of an element writtenin brackets, for example (lithium), substitute the symbol for the element (inthe case of lithium, write Li).

Platinum is a s(iodine)lvery (tungsten)hite met(aluminium)which (iodine)s r(argon)er and more expen(sulfur)ive to(boron)uy than gold. It is (aluminium)so extremelyde(nitrogen)se. A 5 cm cu(beryllium) of pl(astatine)inumha(sulfur) the same ma(sulfur)s as t(helium) average 12-ye(argon)-old!

(boron)y t(helium) sixteenth century, plat(iodine)numw(arsenic) used i(nitrogen) je(tungsten)ellery by In(calcium)Indians in South Ameri(calcium). Plat(iodine)num does(nitrogen)ot react (tungsten)ith oxygen in the air, (sulfur)o itdoes not t(argon)nish. It is (aluminium)so extremely ductile.A si(nitrogen)gle gram of platinum (calcium)n be drawn intoa (tungsten)ire more than a mile lo(nitrogen)g.

When the Conquistadors, who were e(argon)ly Spanishexplorers, vi(silicon)ted South Ameri(calcium), they cameacross this s(iodine)lvery white met(aluminium). They namedit ‘platinum’ after t(helium) Spanish words for ‘(lithium)ttlesilver’. The explorers (beryllium)lieved that eventually theplati(nitrogen)um would turn into silver, and v(arsenic)tamounts of platinum were throw(nitrogen) into the sea int(helium) hope th(astatine) it might ‘ri(phosphorus)en’(iodine)nto silver!

Today pla(titanium)num has many uses including jewellery,in the cat(aluminium)ytic co(nitrogen)verters of c(argon)s,and to treat (calcium)ncer.



A2 All about platinum

– writing frame

CHAPTER

WORKSHEET2

1

Platinum is a s_lvery _hite met_ _ which _s r_ _er and more expen_ive to _uy than gold. It is _ _so extremely de_se. A 5 cm cu_ _ of pl_ _inum ha_ the same ma_s as t_ _ average 12-ye_ _-old!

_y t_ _ sixteenth century, plat_num w_ _ used i_ je_ellery byIn_ _ Indians in South Ameri_ _. Plat_num does _ot react_ith oxygen in the air, _o it does not t_ _nish. It is _ _soextremely ductile. A si_gle gram of platinum _ _n be drawninto a _ire more than a mile lo_g.

When the Conquistadors, who were e_ _ly Spanish explorers,vi_ _ted South Ameri_ _, they came across this s_lvery whitemet_ _. They named it ‘platinum’ after t_ _ Spanish wordsfor ‘_ _ttle silver’. The explorers _ _lieved that eventually theplati_um would turn into silver, and v_ _t amounts ofplatinum were throw_ into the sea in t_ _ hope th_ _ itmight ‘ri_en’ _nto silver!

Today pla_ _num has many uses including jewellery, in thecat_ _ytic co_verters of c_ _s, and to treat _ _ncer.


U

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Information sheet

Elements and symbols

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HAPTER

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Element Symbol Element Symbol

aluminium Al lithium Li

argon Ar magnesium Mg

arsenic As manganese Mn

astatine At mercury Hg

beryllium Be neon Ne

boron B nitrogen N

bromine Br oxygen O

calcium Ca phosphorus P

carbon C platinum Pt

chlorine Cl potassium K

chromium Cr selenium Se

copper Cu silicon Si

fluorine F silver Ag

gold Au sodium Na

helium He sulfur S

hydrogen H titanium Ti

iodine I tungsten W

iron Fe zinc Zn

lead Pb


Name of element ..........................................

Symbol ............................................................

State at room temperature ..........................

Metal or non-metal? .....................................

Magnetic or non-magnetic? .........................

Appearance ....................................................

..........................................................................

Name of element ..........................................

Symbol ............................................................




Appearance ....................................................

..........................................................................

Name of element ..........................................

Symbol ............................................................




Appearance ....................................................

..........................................................................

Name of element ..........................................

Symbol ............................................................




Appearance ....................................................

..........................................................................

Name of element ..........................................

Symbol ............................................................




Appearance ....................................................

..........................................................................

Name of element ..........................................

Symbol ............................................................




Appearance ....................................................

..........................................................................

UN I T

A3 Properties of elementsCHAPTER

WORKSHEET3

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Questions1 Fill in the seven small boxes round the Key with a different colour in each box.2 For each element in the periodic table:

a decide whether it is a metal or non-metal, and fill in the upper right triangle for that element with the correct colour.b decide whether it is a solid, a liquid or a gas, and fill in the left triangle with the correct colour.c decide whether it is a magnetic or a non-magnetic element, and fill in the lower triangle with the correct colour.

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg TI Pb Bi Po At Rn Caesium Barium Lanthanum Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon

Fr Ra Ac Francium Radium Actinium

Al Si P S Cl Ar Aluminium Silicon Phosphorus Sulfur Chlorine Argon

B C N O F Ne Boron Carbon Nitrogen Oxygen Fluorine Neon

Na Mg Sodium Magnesium

Li Be Lithium Beryllium

HHydrogen

HeHelium

solidliquidor gas

metalornon-metal

magnetic ornon-magnetic

KeyPeriod

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1 2 3 4 5 6 7 0 Group

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Complete the following word equations to show how new compounds canbe formed when atoms of different elements are joined together.

1 iron + sulfur � ................................................................................................

2 calcium + chlorine � ......................................................................................

3 magnesium + oxygen � ................................................................................

4 copper + chlorine � .......................................................................................

5 calcium + oxygen � .......................................................................................

6 potassium + chlorine � .................................................................................

7 magnesium + ................................. � magnesium chloride

8 .........................................................+ chlorine � lithium chloride

9 carbon + ......................................... � carbon dioxide

10 .........................................................+ oxygen � sulfur dioxide

A5 Naming new compoundsCHAPTER

WORKSHEET5

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1 Look at the list of materials below:

wood carbon dioxide copper fur grass saltgranite copper carbonate limestone oxygen plastic iron

From the list, name three elements.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(3)

2 Complete the sentences below.

......................................................... are made up of only one type of atom.

......................................................... are formed when two or more differenttypes of atom are joined together.

(2)

3 Consider the four boxes below:

a Which box could represent molecules of the element nitrogen? b Which box could represent molecules of the compound carbon dioxide?c Which box could represent atoms of the element copper?d Which box could represent the compound potassium chloride?

(4)4 Name the element which is represented by the symbol Zn.

..............................................................................................................................

(1)5 A compound has the formula MgO. What is the name of this compound?

..............................................................................................................................

(1)

End of Unit test

Atoms and elements

CHAPTER

1

A B C D

30

6 Name an element which is a liquid at room temperature.

..........................................................................................................................

(1)7 The compound water has the formula H2O.

a How many hydrogen atoms are present in one molecule of water?

..........................................................................................................................(1)

b How many oxygen atoms are present in one molecule of water?

..........................................................................................................................

(1)8 When the metal copper is burnt, it forms a black compound.

a Name the gas, found in air, which reacts with the copper.

..........................................................................................................................

(1)b What is the name of the new black compound which is made?

..........................................................................................................................

(1)c Write a word equation to represent the chemical reaction which has

taken place.

..........................................................................................................................

(1)9 Complete the following word equations:

a zinc + oxygen � .........................................................................................

(1)

b iron + ............................................................................... � iron sulfide

(1)

c calcium carbonate � calcium oxide + .......................................................

(1)

Total marks: 20

Extension questions

10 A compound has the formula CaCl2.

a What is the name of this compound?

b How many atoms of calcium are represented in this formula?

c How many atoms of chlorine are represented in this formula?

d How many atoms in total are represented in this formula?

(4)


Chapter 1 End of Unit test


11 The diagram below shows the reaction between copper carbonate and sulfuric acid.

The equation for the reaction is:

copper carbonate + sulfuric acid � copper sulfate + carbon dioxide + water

During the reaction, the mass of the flask decreased.

Explain how the loss in mass could have occurred.

..........................................................................................................................

..........................................................................................................................

(2)

12 The diagram below shows a coil of magnesium ribbon being heated in a crucible. Occasionally the lid of the crucible is lifted to allow air to reach the magnesium.

The total mass of the crucible and its contents increased during the reaction.


sulfuric acidcoppercarbonate

flask

HEAT

lid

magnesiumribbon

clay triangle

tripod

tongs

crucible


a What is the name of the compound formed?

..............................................................................................................................

(1)b Why did the mass increase?

..............................................................................................................................

(1)

13 Look at this list:

CaCO3

COCoCaOCO2

a Which of these substances is the symbol for an element?

..............................................................................................................................

(1)b Which of these substances is a metal carbonate?

..............................................................................................................................

(1)

Total marks for Extension: 10



Text answers

1 a An atom is a very small particle.b An element is made of only one type of atom.c When atoms of two or more elememts are joined together a compound

is made.2 a C and D

b A and B3 Clockwise from top left: aluminium, element; sand, compound; bromine,

element; plastic, compound; wood, compound; diamond, element4 Hydrogen, fluorine, iodine, boron, sulfur, oxygen5 Mg, Mn, Cl, Ca, Be, Br6 Potassium, iron, gold, silver, tungsten, mercury7 Left hand side8 Right hand side9 More metals

10 Any two from hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon, radon

11

12 a Iron oxide b Aluminium oxide13 a Iron + oxygen � iron oxide b Aluminium + oxygen � aluminium oxide

Literacy activity answersa According to the phlogiston theory, when materials like wood were burnt,

they released/lost a substance called phlogiston. The term phlogiston derived from the Greek word for flame. Once substances were burnt, people believed that they returned to their natural state, which was ash.

b Lavoisier measured the mass of substances before and after they were burnt. He discovered that substances had a greater mass after they were burnt. Lavoisier declared that that this gain in mass proved that substances could not have lost phlogiston.

c Lavoisier suggested that the gain in mass which he observed when substances were burnt was because they had joined with a substance which he called oxygen.

d Lavoisier was the first chemist to distinguish between elements like oxygen and hydrogen, and compounds like water. He showed that compounds could be split into simpler substances, while elements could not be split into anything simpler.

e Despite his support of the revolution, and his own liberal views, Lavoisier was executed because he had been a tax collector.

Atoms and elementsCHAPTER

1

ANSWERS

Formula Type and number of atoms present Element or compound?CH4 1 carbon and 4 hydrogen compoundNH3 1 nitrogen and 3 hydrogen compoundN2 2 nitrogen elementO2 2 oxygen elementHCN 1 hydrogen, 1 carbon and 1 nitrogen compoundCO 1 carbon and 1 oxygen compoundCl2 2 chlorine element

34

End of chapter answers

1 a True b False c False d True e True2 a D b B and D c A and C d B e D f A g C3 a Cobalt

b Carbon, oxygen and cobaltc O2 and Cd Carbon monoxide and carbon dioxide

4 a Moleculeb Compoundc Symbold Elemente Atom

5 a symbols, elementsb letter, C, name, chlorine, first, secondc Latin

Worksheet answers

A1 Elements wordsearchIn any order: oxygen, gold, silver, copper, sodium, hydrogen, helium,nitrogen, magnesium, calcium, neon, argon, chlorine, bromine, iodine, iron,zinc, lead, aluminium, platinum

A2 All about platinumPlatinum is a sIlvery White metAl which Is rArer and more expenSive to Buythan gold. It is Also extremely deNse. A 5 cm cuBe of plAtinum haS the samemaSs as tHe average 12-yeAr-old!

By tHe sixteenth century, platInum wAs used iN jeWellery by InCa Indians inSouth AmeriCa. PlatInum does Not react With oxygen in the air, So it doesnot tArnish. It is Also extremely ductile. A siNgle gram of platinum Can bedrawn into a Wire more than a mile loNg.

When the Conquistadors, who were eArly Spanish explorers, viSited SouthAmeriCa, they came across this sIlvery white metAl. They named it ‘platinum’after tHe Spanish words for ‘Little silver’. The explorers Believed thateventually the platiNum would turn into silver, and vAst amounts ofplatinum were throwN into the sea in tHe hope thAt it might riPen Intosilver!

Today plaTinum has many uses including jewellery, in the catAlyticcoNverters of cArs, and to treat Cancer.

A5 Naming new compounds1 iron sulfide2 calcium chloride3 magnesium oxide4 copper chloride5 calcium oxide6 potassium chloride7 chlorine8 lithium9 oxygen

10 sulfur


Chapter 1 Answers


End of Unit test answers

1 copper, iron, oxygen (3)2 elements; compounds (2)3 a B b C c A d D (total 4)4 zinc (1)5 magnesium oxide (1)6 bromine or mercury (1)7 a 2 (1) b 1 (1)8 a oxygen (1)

b copper oxide (1)c copper + oxygen � copper oxide (1)

9 a zinc oxide (1)b sulfur (1)c carbon dioxide (1)

Total marks: 20

Extension answers

10 a calcium chloride (1)b 1 (1)c 2 (1)d 3 (1)

11 either loss/evaporation of water (1);or loss/escape of carbon dioxide (1)

12 a magnesium oxide (1)b magnesium combines/joins with oxygen (1)

13 a Co (1) b CaCO3 (1)


Suggested levels for marks gained

5–14 working towards level 415–24 working towards level 525+ working towards level 6

Chapter 1 Answers

Pupils should be familiar with the following ideas:• Know that light travels from a source• Distinguish between opaque and transparent materials• Relate shadow formation to opaque materials• Know that light is reflected from shiny surfaces• Know that we see things only when light from them enters our eyes

2 Light

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Starting points


AbsorbBoundaryColour blindnessColour filterDispersionDyeImage

Laterally invertedLuminousNon-luminousNormalObjectOpaquePeriscope

PigmentPlane mirrorPrimary colourRay diagramReflectedReflectionRefraction

Secondary colourShadowSpectrumTranslucentTransparentVirtual imageWhite light

In this topic pupils should learn:• to build on their knowledge of light and its effects• to learn that we see luminous objects by the light they emit• to learn that we see non-luminous objects by the light they reflect• to represent light as a ray• to use the concept of rays to explain reflection and refraction• to understand how virtual images are formed and that an image is laterally

inverted• to use dispersion to separate white light into the seven colours of the spectrum• to make and test predictions about the path of light• to measure and record angles• to investigate reflection and refraction at a plane surface• to investigate the effects of coloured light on the appearance of objects

Learning checklist

Links

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Links with the Key Stage 2 Scheme of Work

Unit Title3F Light and Shadows6F How We See Things


CH A P T E R

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Cross-curricular linksArt and design: Objects and Viewpoints.

LiteracyThere is a literacy exercise on the compact disc in the Pupil Book.

NumeracyAngles need to be measured and drawn, using a protractor.

2 Light

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Most pupils

Scientific enquiry• Make measurements of light intensity• Make predictions about the reflection of light at plane surfaces• Measure angles with precision• Frame a question about light and colour and plan how to investigate itPhysical processes• Recognise that light travels in straight lines at high speed• Represent the path of light by rays• Describe how light is reflected and refracted at plane surfaces• Explain the origin of colour in the dispersion of white light• Describe the effects of coloured filters and different coloured lights on the

appearance of coloured objects• Give an example of how colour is important in everyday life


Scientific enquiry• Classify materials as opaque, transparent, translucent, reflectors or absorbers• Identify patterns in angular measurements of reflected rays of light• Investigate a question about colour and lightPhysical processes• Describe how light is reflected at plane surfaces and describe reflected images• Describe the effect of a prism on white light• Recognise that filters and coloured objects absorb some colours and transmit or

reflect others


Scientific enquiry• Draw conclusions from their data• Make predictions about image formation using the law of reflection or the

patterns of behaviour from refraction• Make sufficient observations when investigating colour to draw valid conclusionsPhysical processes• Calculate the time for light to travel• Explain the appearance of coloured objects in coloured lights

Learning outcomes



Unit Title8L Sound and Hearing

38


Most pupils will already be aware that the further they move from a light sourcethe smaller and less bright it appears to become. The topic is introduced andthese ideas confirmed by considering the appearance of a lighthouse, the Moonand the Sun seen at different distances. Using the same examples we can justtouch on the question of ‘How long does it take light from a source to reach us?’Three examples are given to emphasise that light travels very quickly and thatover small distances its arrival is almost instantaneous.

How does light travel?Again many pupils may already have developed the idea that ‘light travels instraight lines’. This idea can be reinforced both from everyday experiences suchas car headlights in the dark, and beams of sunlight breaking through clouds orthe trees of a forest. Examples of these instances can be seen in the Pupil Book.Practical reinforcement can come from the two experiments described inWorksheet B1, Light travels in straight lines. Looking through the three holes inthe screens and being able to see an object at the far end confirms that lighttravels in straight lines. Moving one or more of the screens and then being unableto see the object confirms that light cannot, on its own, bend around corners.Looking (or shining a light) through a straight and then curved piece of tubingconfirms the same idea. More able pupils may see the link between lighttravelling in straight lines and the shapes of shadows. A paper exercise of drawingobjects and their shadows similar to that mentioned at the end of Worksheet B1would confirm this link.

Ray diagramsWe can now develop the idea that because light travels in straight lines we canuse ray diagrams to show what is happening. Very useful examples to use hereare ray diagrams to explain how we see luminous and non-luminous objects. Aray diagram to illustrate this is found in the Pupil Book, followed by some simplequestions to consolidate the principle. Encourage pupils to draw arrows on theirlight rays to show the direction in which the light is travelling.

Transparent, opaque and translucentMany pupils will probably already know the words transparent and opaque butsome will not. An explanation of the meanings followed by lots of examples usingobjects at hand should ensure a sound understanding by all. It would be helpfulto give examples of the usefulness of such materials, e.g. transparent when youwant to see through – windows, fish tanks, etc. – and opaque where you may notwant to be able to see through – walls and doors, screens, etc. During the courseof this discussion it may well come to light that not all windows are see-through.This is an opportune time to introduce the idea of translucent materials. Havingsome examples available such as frosted glass, tracing paper and a fabriclampshade, will help greatly. If appropriate, the idea of shadows and light beingblocked off by an opaque object can be dealt with here. Question 7 givesopportunities for pupils to confirm what they have learned.

ReflectionWorksheet B2, Reflection of light, provides pupils with the opportunity to predictwhat they think will happen when a ray of light strikes a plane mirror and then toconfirm their ideas using basic equipment such as ray boxes, mirrors andprotractors. Pupils should look for a general trend from their results as thisexperiment rarely gives accurate results (inaccuracies are often caused by thereflecting surface being covered by a layer of glass). It is fine to conclude that the


39

ray is reflected off the mirror at the same angle that it hits it. For many students itis an opportunity to introduce the idea of drawing in a normal and measuring theangle of incidence and the angle of reflection of a ray. This can then lead to themore usual Law of Reflection, i.e. the angle of incidence is equal to the angle ofreflection.

Because rays of light are reflected in a predictable way they are often used inoptical instruments. A good example of this is the periscope. Pupils could be askedto make their own periscope using the directions given in Worksheet B3,Periscopes and kaleidoscopes. Pupils could be asked the previous lesson to bring intubes of an appropriate size, i.e. 8–10 cm diameter and about 25 cm long.Alternatively, a ready-made or purchased periscope could be made available.

Images created by a plane mirrorMost pupils will look at an image of themselves sometime during the day. This canbe used as a starting point to ask the questions ‘Where is your image?’, ‘Does itreally exist?’, ‘What does it look like?’, ‘Can we explain, using a ray diagram, howyour image has been created?’ Worksheet B4, Finding the image in a plane mirror,uses triangulation with pins to find the position of the image of an object. Pupilswill discover that the image is as far behind the mirror as the object is in front. Iftime permits they can repeat the experiment with the object pin at differentdistances from the mirror.

Using the diagram on page 24 of the Pupil Book or by constructing one on theboard pupils can be shown how we see an image in a plane mirror and why thisimage does not really exist. No light passes through it. It is a virtual image.

The other properties of the image, e.g. size and lateral inversion, can be teased outof pupils while they still have the mirrors to look at. If time permits, or forhomework, pupils could be asked to do some work on mirror writing to confirmtheir understanding of lateral inversion.

Again, time permitting, pupils could be asked to make a simple kaleidoscope as shownon Worksheet B3, Periscopes and kaleidoscopes, and then explain what they see.

RefractionPupils could be shown some effects of refraction, e.g. pencil or ruler half-immersedin water appearing to be bent, to introduce the topic. They could then carry outthe experiment described in Worksheet B5, What happens to a ray of light as ittravels through a glass block? Pupils will readily see from their results that the ray oflight changes direction at the air/glass boundary. They can be led to the idea thatthe ray bends towards the normal as it enters the block (because it slows down)and it bends away from the normal as it leaves the block (because it speeds up).This change in direction caused by a change in speed is called refraction. This canthen be linked to some of the effects already mentioned and others, including thecoin and mug experiment, real and apparent depth of ponds and pools.

DispersionPupils can be shown that when white light passes through a prism it can be madeto split up into its component colours. This process is called dispersion. This couldbe done as a demo or class experiment. It and the recombination of the colours tomake white light can be seen in the Pupil Book on pages 28–29. This can bereinforced by following the instruction in Worksheet B6, Newton’s disc.

The order of the colours produced by dispersion with a prism are the same order asthose in a rainbow and can be memorised using the mnemonic Richard Of YorkGave Battle In Vain (Red, Orange, Yellow, Green, Blue, Indigo, Violet). Thedispersion that causes a rainbow is caused by water droplets in the air.

2 Light


Mixing coloured lightsUsing coloured lights shone onto a screen or using the picture shown on page 29of the Pupil Book, pupils can be shown that when coloured lights overlap theyproduce new colours. There are, however, three colours that cannot be producedby mixing other colours. These are red, blue and green. They are called theprimary colours. All other colours can be made by mixing these three in differentproportions. If equal amounts of any two primary colours are mixed together theyproduce the secondary colours yellow, cyan and magenta. This can besummarised in the colour triangle shown on page 29 of the Pupil Book. Question13 on page 29 of the Pupil Book can be used to practise using the colour triangle.

Seeing coloured objectsUsing the examples in the Pupil Book on page 30 or using coloured objects in theroom it can be explained to pupils that when light hits an object some of thecolours in the light may be absorbed by the object and some reflected. The lightthat is reflected determines the colour we see and this in turn is determined bypigments or dyes present in an object. An object containing red dye reflects redlight and absorbs all others, etc. Drawing lots of examples in their books may helppupils grasp the concept.

Coloured filtersSome objects are transparent or translucent and therefore will allow light to passthrough them, i.e. allow light to be transmitted through them. Using plasticfilters pupils can grasp that a filter transmits (allows through) certain colours butabsorbs others. Worksheet B7, Coloured lights, provides the opportunity forpupils to confirm their understanding of coloured lights and coloured filters.

40

How does light travel?In Worksheet B1, Light travels in straight lines, although pupils can use any objectto look at through the holes in the screens, a luminous object provides fewerconceptual problems, i.e. it is emitting light. If a Bunsen flame is used as the lightsource it will be necessary to go over safety issues such as tying back hair andtucking in ties. For this reason the use of electric light bulbs might be preferable ifthey are available.

Looking through a length of Bunsen tubing straight and then curved is a possiblevariation on the above experiment. As an extra demonstration, if a torch ofappropriate size is available, light could be shone down a length of tubing onto ascreen. The light would be seen to emerge only if the tubing was straight.

ReflectionThe experiment described in Worksheet B2, Reflection of light, lends itself to theidea of getting pupils to predict what they think they will discover from theexperiment and give some reasons for their prediction. Where possible a semi-blackout should be used for this experiment as it helps pupils to see the incidentand reflected rays more easily.

Safety point: Make sure ray boxes have been checked for electrical safety.

Breakage of ray box bulbs happens because pupils connect the bulbs to theincorrect voltage. Where a variable voltage is being used pupils will need to betold the correct voltage in strong terms, i.e. ‘use 12 V and no more’. This problemcan be overcome by using power supplies where the maximum voltage can be



!

41

2 Light

preset or better still using power supplies that have connections dedicated to theuse of ray boxes.

The other major cause of breaking bulbs is continually turning them on and off. Itis a good idea to tell pupils, as they are about to start their experiment, to leavethe bulbs turned on until they have completed the whole experiment.

Sometimes pupils cannot see a reflected ray. This is usually because their mirror isleaning backwards and the reflected ray is above the plane of the paper. Tiltingthe mirror forwards slightly should produce a reflected ray on the paper.

The results from this experiment are rarely accurate, so it may be a goodopportunity to talk about experimental error and looking for a general trendrather than perfect results.

Worksheet B3, Periscopes and kaleidoscopes, describes a fun lesson that usefullybuilds on the ideas from Worksheet B2, Reflection of light. Pupils were asked inthe previous lesson to bring in one cardboard tube each with a diameter of about 10 cm (it does not have to be accurate) and at least 25 cm long. Pupils then getthe feel that they are making their own periscope rather than rebuilding one thatsomeone else used last year or last week. Some may even want to take themhome. That’s fine but make sure that all the mirrors are returned!

Having as many pairs of strong scissors as possible helps with this experiment.Cutting stiff cardboard with small scissors is a nightmare. Having several reels ofsticky tape about the lab avoids possible bottlenecks during the experiment.

Making the kaleidoscope is easy and good fun. Getting enough light into it sothat the shapes and patterns can be seen is not so easy. The following ideas mighthelp. Make the base of the kaleidoscope from tracing paper or perhaps even astrong see-through plastic such as polythene. Use translucent coloured shapes,e.g. cut-up pieces of thin plastic. Allow light to get into the top of thekaleidoscope by positioning your eye 1 or 2 cm above the top.

Images created by a plane mirrorOne of the biggest problems with the experiment in Worksheet B4, Finding theimage in a plane mirror, is getting the pins to stick in. Some pupils resort to hittingthe pins and this usually bends them, making them useless for future experiments.A word of warning before starting may save you some money! One possiblesolution is to do the experiment on a piece of soft wood. Pushing the pins in byhand is then very easy.

This experiment nearly always produces results that show the image distance isslightly larger than the object distance. The reason for this is often the thicknessof the glass at the front of the mirror. If pupils get the back of their mirrors to siton the line they have drawn on their piece of A4 paper this should reduce theproblem.

Optical pins often go missing in lessons like this. Counting them out at thebeginning of the lesson and at the end (in front of the class) may help reducelosses.

RefractionAs in the experiment described in Worksheet B2, Reflection of light, a semi-blackout should be used for the experiment in Worksheet B5, What happens to aray of light as it travels through a glass block?, and all the precautions about rayboxes, correct voltages and turning bulbs on and off apply again.



The passage of the ray through the glass block is often not visible (the ray maybe travelling slightly above the paper beneath the block). But because its path inand out of the block is known, its path within the block can be assumed.

When pupils are asked which way the ray bends as it crosses the boundary theyinvariably say to the left, to the right, up, down, etc. Pointing out to them thatwhile these are all correct answers, there is a problem with them. By changingthe position from where they are looking at the block, right now becomes leftand up now becomes down. We need to look for a description that does notchange when we change our viewing position. This neatly leads to the idea oflight bending towards or away from the normal.

The mug and coin experiment is a nice one to try at home and involves all thefamily. The idea behind it and the explanation can be extended a little by askingany keen anglers in the class why they should sit well back from the edge of thebank when fishing just a few metres out, i.e. they will then be out of sight of thefish even after the light has been refracted.

Water in ponds, pools, lakes, etc. will always seem shallower than it really is.This again is due to refraction. In general, water appears to be only two-thirds ofits real depth.

DispersionWorksheet B6, Newton’s disc, describes an experiment that all pupils enjoy buttime may be a problem so pupils need to be kept on task. As with the periscope,if pupils are going to cut out their own discs a good supply of stiffish card isneeded (card from cardboard boxes works well as long as it is not corrugated)and lots of pairs of strong scissors.

The colours from coloured pencils can be a bit faint, so if pupils are going to usepencils tell them to press hard. Felt tips would be preferable. Most pupils willneed help with identifying indigo or violet. Labelling these before the lesson willsave time later. Beware pupils who want to gather all seven colours beforebeginning colouring. This is bound to lead to bottlenecks when time is tight.

It is crucial to get the holes and their positioning right. The holes must be justbig enough to pass the thread through. The disc will not spin very well if theholes are too large. More importantly, the holes must be accurately positionedan equal distance either side of the centre of the disc. Getting this incorrect is thegreatest cause of the disc not working. It becomes unbalanced. The distance fromthe centre is not quite so crucial; about 1.5 cm seems to work fine.

Lastly, if you have not done this before and are unsure how to get the discspinning and keep it spinning, have a go well before the lesson. It is not difficultbut there is a knack. Usually by showing one group how to do it the methodcascades through the class. It is one of those things where showing is better thanexplaining. While you are all having fun, do not forget to point out to the pupilsthat all the colours have mixed to produce white.

Coloured filtersGood fun, but beware the pitfall with primary colours in Worksheet B7,Coloured lights. Artists will tell you that red, green and blue are not the primarycolours. However, scientists are not mixing colours (paints, pigments, etc.), butcoloured lights.

It is always a good idea when teaching this topic to have a poster on the wall ora small diagram on the board showing the colour triangle.

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Using familiar objects around them, pupils in turn like to explain why colouredobjects look the colour they do. After giving them three or four examples they areusually keen to jump in with their own.

Coloured objects in coloured lights present more difficulties. It is important tostart with the primary colours. Where appropriate the more able pupil may beable to deal with lights and objects with secondary colours. A useful tip here is tolook for a common colour between the light and the object. If there isn’t one, theobject will look black.


Sc1

Scientific Enquiry

1c, 2g (partially),2h ,2k, 2m, 2p

Sc2


Sc3


Sc4

Physical Processes

3a, 3b, 3c, 3d, 3e,3f


What I have learnt

Light


Shadow

Colour filter

Dye

Image

Primary colour

Laterally inverted

Pigment

Colour blindess

Dispersion

Non-luminous

Object

Plane mirror

Reflection

Luminous

Absorb

Opaque

Normal

Periscope

Ray diagram

White light

Reflected

Refraction

Secondary colour

Spectrum

Transparent

Translucent

Virtual image

Boundary


• I know that we see luminousobjects by the light they emit

• I know that we see non-luminousobjects by the light they reflect

• I know that light can be shown as a ray

• I can use rays to explain reflectionand refraction

• I know that white light is a mixtureof coloured lights

• I know that white light can beseparated into the seven colours ofthe spectrum

• I can measure angles

• I can investigate reflection andrefraction at a plane surface

• I can see how coloured light affectsthe appearance of objects

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CHECKLIST

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Lesson Focus Pupil Book 2 pp. 19–21Light travels very quickly. Light travels in straight lines

Expectations

Most Pupils Understand that light travels very quickly and in straight lines andcan provide some evidence to support these ideas. Understand thatthe appearance of light sources changes with distance.

Less Able Pupils Understand that light travels very quickly and in straight lines.Understand that the appearance of light sources changes withdistance.

More Able Pupils All the above and can explain why the appearance of light sourceschanges with distance and can calculate the time for light to travel.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: More able pupils may be able to calculate the time it takes for light to travel certain distances.ICT:


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Worksheet B1 Light travels in straightlinesThree screens with small central holeLength of thread (approx. 60 cm)Luminous object, e.g. light bulbLength of Bunsen tubing (approx. 30 cm)

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10 In and register. More able pupils, given the speed of light, can Pupils appreciate that light travels very quickly, so quickly that Starter. Q and A session with whole class. Where does most of our light come calculate how long it takes for light to travel a in most situations we can consider that it arrives from? How does it get here? How long do you think it takes to get here? variety of distances, e.g. once around the world. instantaneously, e.g. when turning on a light bulb.Using the information on page 19 of the Pupil Book, pupils can see how long it More able pupils may make the comparison takes light to travel long and short distances. between the speeds of light and sound, using

thunder and lightning as their example. (This is mentioned in more detail in Chapter 6 Sound and Hearing.)

10 Development. Ask pupils how the appearance of a light source, e.g. the Pupils appreciate change in apparent size and brightness as lighthouse, would change if the distance between it and them increases/ distance between light source and observer changes.decreases.Pupils then answer questions 1, 2 and 3 on page 20 of the Pupil Book.

20 Pupils are asked to look at the photograph on page 20 of the Pupil Book and More able pupils will be able to suggest more Light travels in straight lines.are then asked if the picture suggests ‘how light travels’. Perhaps they can examples that suggest that light travels in straightsuggest other examples that lead to the same idea, e.g. car headlights, lines.search lights.Pupils carry out the two experiments described in Worksheet B1 Light travels in straight lines to confirm that light does travel in straight lines.Pupils then carry out steps 11–14.

10 Plenary. Pupils discuss all that they have discovered about light during the Pupils can give examples to support the idea that light travels lesson, emphasising how the observations they have made confirm that light in straight lines.travels in straight lines.

Homework: Under the heading ‘Light travels in straight lines’ pupils should describe the experiments they carried out and explain in their own words why the observations they made support the idea that light travels in straight lines.


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Lesson Focus Pupil Book 2 pp. 21–22Transparency and shadows

ExpectationsMost Pupils Can explain how we see luminous and non-luminous objects. Can

explain the difference between transparent, opaque andtranslucent objects, and give examples.

Less Able Pupils Can give some examples of luminous and non-luminous objects.Know that light can pass through some objects but not others andcan give some examples.

More Able Pupils All the above and can use the words transmit, reflect and absorbwhen explaining what may happen to a ray of light when it strikesan object.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Pupils understand and can use in context the terms transparent, opaque, translucent, luminous and non-luminous.Numeracy:ICT:


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Demo: Transparency, translucency and opacity

Several sheets of clear glass and plasticSeveral sheets of tracing paper andfrosted glassSeveral sheets of cardOptional: fabric lampshade

Pupil Book

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10 In and register. More able pupils will provide more information Consolidation that light travels very quickly and in straight Starter. Quick Q and A session to remind pupils of what they did and what they about what they learned from the last lesson. lines.discovered last lesson.

5 Development. Continue with Q and A to introduce new ideas. Why is light important to us? What do we use it for? What do we call objects that give off light? How do we see them? What do we call objects that do not give off light? How do we see them? The diagram on page 21 of the Pupil Book shows how we see luminous and non-luminous objects.

15 Pupils put the heading in their books ‘Seeing Objects’, copy the diagram on Less able pupils may need help with unfamiliar Pupils understand the difference between luminous and non-page 21 and then in their own words explain how we see luminous and words such as luminous and non-luminous. luminous objects and can give several examples of each. non-luminous objects. Pupils can explain how we see luminous and non-luminous Pupils answer in their books questions 4, 5 and 6 from page 21 of the objects.Pupil Book.

10 Using the diagrams on pages 21 and 22 of the Pupil Book or objects in the room, More able pupils will more readily use these new, Pupils understand the meanings of the words transparent, e.g. sheets of glass, tracing paper and cardboard, introduce pupils to the idea unfamiliar words and in the correct context. opaque, translucent, transmit, reflect and absorb.that objects can be transparent, opaque or translucent. Having at hand several Less able pupils may need constant reassurance pieces of tracing paper or frosted glass will help pupils appreciate the meaning that they are using the new words correctly.of the word translucent. Encourage pupils to use the words transmit (allow through), absorb and reflect in their descriptions of what happens to light as it tries to pass through the various objects.Pupils draw labelled diagrams to illustrate transparent, opaque and translucent objects.

10 Plenary. Do question 7 from page 22 of the Pupil Book as a whole class oral Pupils understand how materials with different properties are activity. used in different situations.Remind pupils that the last part of the worksheet they did in the previous lessons was looking at shadows. Tonight’s homework is going to be about shadows.

Homework: Answer the following questions in your book. What is a shadow? How is a shadow formed? (Draw a diagram.) What does the shape of a shadow tell you about how light travels? Ask pupils to find a thick cardboard tube with a diameter of about 10 cm and at least 25 cm long to bring for the next lesson.


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Lesson Focus Pupil Book 2 pp. 23–26Reflection of light

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy:ICT:


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Worksheet B2 Reflection of lightPer group:Ray box and power supplySmall plane mirrorTwo small pieces of plasticineA4 paperRulerProtractor

Worksheet B3 Periscopes andkaleidoscopesPer group:Three small mirrorsCardboard or plastic tube (approx. 10 cmdiameter)Sticky tapeSmall pieces of coloured plastic or paperScissorsTracing paper

ExpectationsMost Pupils Will be able to measure angles accurately so that they can make

predictions about the reflection of light from plane surfaces.Know that a ray of light is reflected from a plane mirror such thatthe angle of incidence is equal to the angle of reflection.Know that because rays of light are reflected from a plane mirror ina predictable way mirrors are used in optical instruments such asperiscopes and kaleidoscopes.

Less Able Pupils Know that rays of light are reflected from a plane mirror at thesame angle as they hit it. Know that some optical instrumentscontain mirrors.

More Able Pupils All the above and will be able to explain the purpose of planemirrors in some optical instrument.

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10 In and register. Pupils consolidate their ideas about shadows.Starter. Go over homework. Quick Q and A session. What is a shadow? How is it formed? What does the shape of the shadow suggest about light?

15 Development. What happens to a ray of light that strikes a mirror? It is Less able pupils may need support to ensure that Pupils can measure the angle of incidence and the angle of reflected. Pupils carry out the experiment described on Worksheet B2 they are able to use a protractor and that they reflection of a ray.Reflection of light. are measuring the correct angles. Pupils recognise that a ray of light is reflected from a plane

mirror at the same angle as it strikes the mirror.

5 Pupils put a heading in their books ‘Reflection from a plane mirror’. They then More able pupils will draw a more accurate, Pupils are able to draw a ray diagram.draw a labelled diagram similar to that shown on page 24 of the Pupil Book. labelled ray diagram.Insist that pupils use a ruler to draw the light rays and show the direction that the light is travelling, using arrows. Beneath the diagram they write the sentence ‘A ray of light is reflected from a plane surface at the same angle as it hits it’, i.e. the angle of incidence is equal to the angle of reflection.

15 A periscope is an optical instrument that uses plane mirrors to reflect light in a Pupils recognise how plane mirrors can be used in some useful way. (See page 23 of the Pupil Book.) A kaleidoscope also contains plane optical instruments.mirrors. Using Worksheet B3 Periscopes and kaleidoscopes pupils construct either a periscope or a kaleidoscope or both if time permits.

5 Plenary. Quick discussion with pupils about what they have discovered about how rays of light are reflected from a plane mirror and how mirrors can be used in optical instruments.

Homework: Find out (a) how rays of light are reflected from curved mirrors and (b) where we make use of curved mirrors.


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Lesson Focus Pupil Book 2 pp. 23–26The images created by a plane mirror

Expectations

Most Pupils Know that the image created by a plane mirror does not reallyexist. This image is laterally inverted, the same size as the objectand is as far behind the mirror as the object is in front.

Less Able Pupils Know that mirrors create images of objects placed in front of themand can describe some features of these images.

More Able Pupils All the above and can draw an accurate ray diagram to show howa plane mirror creates a virtual image.



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Worksheet B4 Finding the image in aplane mirrorPer group:Five optical pinsSmall plane mirrorTwo small pieces of plasticineA4 paperRulerOptional: softwood boards to put opticalpins in

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10 In and register. Pupils consolidate and develop their ideas about the usesStarter. Go over homework as whole class Q and A session. Tease out the of different mirrorsfollowing facts. Some curved mirrors reflect light so that the rays come together or converge. Others reflect the light so it spreads out or diverges. How many uses could you find for curved mirrors – rear view mirror in a car, shaving/make-up mirror, concealed entrance mirror, etc.

20 Development. Give the pupils a plane mirror. Ask them to look into it and Pupils know that the position of an image is as far behind the answer the question ‘What can you see?’ Get the answer that they can see mirror as the object is in front.images of objects. Then ask the question ‘Where are those images?’ Where necessary lead them to the answer ‘The images are somewhere behind the mirror’.Pupils now carry out the experiment described in Worksheet B4 Finding the image in a plane mirror.

10 Using a ray diagram similar to that on page 24 in the Pupil Book pupils are More able pupils are able to explain how a virtual Pupils understand how an image is formed behind a plane shown how the reflection of light from a plane mirror creates an image behind image is created by a plane mirror. mirror.the mirror. Emphasise that the image does not really exist. It is a virtual image. Less able pupils know that the eye sees an image Pupils should put a heading in their book ‘The image created by a plane mirror’. of an object behind the mirror.Then the diagram mentioned above should be copied accurately.

10 Plenary. Using a Q and A session while looking into their mirrors, or using More able pupils can explain more clearly the Pupils know that the image created is the same size as the the diagrams drawn on pages 23 and 24 of the Pupil Book, pupils should spot meaning of lateral inversion and give more object and is laterally inverted.the other properties of an image created by a plane mirror, i.e. lateral inversion examples.and image being the same size as the object. Pupils should make a note of these properties in their book and, if time allows, draw diagrams to illustrate these properties.

Homework: Answer questions 8 and 9 from page 26 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 26–27Refraction of light

ExpectationsMost Pupils Can describe how light is refracted at the boundary between two

media. Know that refraction can cause some strange visual effects.

Less Able Pupils Know that light may change direction as it moves from onemedium into another. Know that this change in direction isresponsible for producing some strange visual effects.

More Able Pupils All the above and can make predictions about what will happen toa ray of light as it crosses the boundary between two media.



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Demo: RefractionBeakerWaterPencil or ruler

Worksheet B5 What happens to a rayof light as it travels through a glassblock?Per group:Ray box and power supplyRectangular glass blockA4 paperRuler

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10 In and register. More able pupils may be able to suggest that Starter. Pupils are shown how a pencil or ruler half immersed in a beaker of something is happening to the light coming from water looks bent. Why does it look bent? By the end of the lesson you should the part of the ruler beneath the surface of the be able to say why this happens. water.

15 Development. Pupils carry out steps 1–8 of the investigation described in More able pupils will see the pattern and be able Pupils see that a change in direction occurs at the boundaryWorksheet B5 What happens to a ray of light as it travels through a glass to predict the direction in which a ray bends, i.e. between different media.block? Careful questioning during the experiment will pinpoint the key the ray bends towards the normal as it enters a Pupils can predict the direction in which a ray will bend as it observations to be made. more dense medium and away from the normal crosses the boundary between two media.The light changes direction as it enters the glass block. when it enters a less dense medium.The light changes direction when it leaves the glass block. Less able pupils will recognise that the ray does Asking which way the ray bends can eventually lead to idea that the ray bends change direction as it enters and leaves the glass towards the normal as it enters the glass block and away from the normal as it block.leaves the glass block.Answers such as it bends to the right or left or up or down are acceptable but all of these answers change if you change the position from which you are viewing the block and therefore are not ‘good’ descriptions.

10 This change in direction is called refraction. Pupils write the heading ‘Refraction’ in their workbooks and then draw accurate ray diagrams similar to those on page 27 of the Pupil Book, showing refraction towards the normal and away from the normal. At the side of each diagram a small description should be given, e.g. ‘When a ray of light enters a less dense medium it bends away from the normal’.

10 Pupils answer question 3 and compare their observations with those described Pupils realise that if a ray crosses the boundary between two on page 27 of the Pupil Book. media at 90° there is no change in direction.

5 Plenary. Referring back to the bent pencil/ruler observed at the beginning of the lesson, pupils should now be able to explain that the ‘false’ image is created because rays of light bend as they cross the water/air boundary. There is a diagram on page 26 of the Pupil Book which shows this in detail.

Homework: Coin and mug experiment as described in Worksheet B5 steps 9–11 and question 5.


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Lesson Focus Pupil Book 2 pp. 27–29Dispersion of white light by a prism to produce a spectrum of coloursRecombination of spectrum of colours to produce white light

Expectations

Most Pupils Can identify the colours of the spectrum. Can identify how whitelight is dispersed by a prism to produce a band of colours called aspectrum. Understand that the colours in the spectrum can berecombined to form white light.

Less Able Pupils Know that white light is a mixture of colours.

More Able Pupils All the above and can name the colours of the spectrum in order.Recognise that rainbows are also produced by dispersion.



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Demo or class experimentGlass prismsPossible source of light needed, e.g. raybox

Worksheet B6 Newton’s discPer group:One compassOne piece of stiff card approx. 15 cmsquarePair of scissorsColoured felt tips or pencils1 m of thread

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10 In and register. More able pupils will know more facts about Starter. Q and A session. What is a rainbow? Where do we see a rainbow? rainbows and be able to make more contributions What are the colours of the rainbow? Are they always in the same order? to the class discussion.What order? Pupils can be shown the picture of a rainbow on page 28 of the Pupil Book.

15 Development. A famous scientist called Sir Isaac Newton demonstrated that he Less able pupils may need some help in describing Pupils understand that white light can be dispersed to give a could produce a band of colours similar to a rainbow using a glass prism. Pupils less familiar colours such as indigo and violet. band of colours.can be shown this as a demo with a large prism, or given smaller prisms, may More able pupils may be able to suggest reasons try to do this for themselves. Pupils should note that the colours are always in why the colours have been dispersed, i.e. each the same order. This order can be memorised using the mnemonic Richard Of colour is refracted by a different amount by the York Gave Battle In Vain. Newton suggested that white light was made up of prism.these coloured lights mixed together and that the prism was separating them. This separation is called dispersion and the band of coloured lights is called a spectrum.

5 Newton went one step further to prove his idea was correct by using a second Pupils understand the colours can be recombined to produce inverted prism to make the light recombine to produce white light. Pupils can white light.try this but, if it is difficult to see, there is a picture on page 28 of the Pupil Book showing the recombination of the colours.

20 Plenary. Use Worksheet B6 Newton’s disc. Pupils make and play with a Confirmation that mixing coloured lights can produce white Newton’s disc. If time is short, pupils can be provided with ready-made discs. light.

Homework: Questions 10–12 on page 29 of the Pupil Book.


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Lesson Focus Pupil Book 2 p. 29Mixing coloured lights to produce new coloursThe colour triangle

Expectations

Most Pupils Understand that mixing coloured lights can produce new coloursand, using the colour triangle, can predict what these new colourswill be.

Less Able Pupils Understand that mixing coloured lights can produce new colours.

More Able Pupils All the above.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Pupils will express in their own words the effects of mixing coloured lights.Numeracy:ICT: Some ICT programs will allow pupils to mix colours and see the results.


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Demo: Mixing coloured lightsThree light sources, one red, one blueand one greenA white screen

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10 In and register. More able pupils may be able to describe the Pupils understand that mixing coloured lights can produce Starter. Remind pupils by Q and A session that white light is a mixture of new colours produced more accurately. new colours.coloured lights. The apparatus we are about to use is going to investigate what happens when we mix two or perhaps three coloured lights.With semi- or complete blackout a red light, a green light and a blue light are shone on a white screen. Pupils are asked to identify those areas where the lights overlap and what colours they produce.

15 Development. There are three colours that cannot be produced by mixing Less able pupils may need some help in Pupils are able to predict what colours are produced when coloured lights. These are red, green and blue and are called the primary recognising new colours, e.g. cyan and magenta. two primary colours are mixed.colours. Use the apparatus to show that when equal amounts of two primary colours are mixed, secondary colours are produced. These are yellow (red and green), magenta (red and blue) and cyan (blue and green). Summarise all these mixes using the colour triangle.

15 In their books pupils draw the colour triangle and explain in their own words what it shows. Information on page 29 of the Pupil Book may help pupils do this.

10 Plenary. Pupils do question 13 from page 29 of the Pupil Book to confirm they Less able pupils may need some help in using Pupils are able to use the colour triangle.know how to use the colour triangle. the colour triangle.

Homework: Pupils answer questions 7 and 8 on page 37 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 30–33Seeing coloured objectsThe effects of coloured filters

ExpectationsMost Pupils Understand that coloured objects reflect some colours and absorb

others. Understand that coloured filters absorb some colours oflight and transmit others.

Less Able Pupils Understand that a coloured object reflects its own colour of light.Understand that a coloured filter lets its own colour of light passthrough and blocks other colours.

More Able Pupils All the above and are able to predict what colour of light isreflected from an object and explain why. Are able to predict whatcolour of light can pass through one or more filters.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Pupils are asked to describe in their own words why coloured objects are seen as having those colours and the

action of filters.

Numeracy:ICT:

Cross-curricular developmentThe use of coloured filters in stage lighting will be of relevance to those pupils following a performing arts course.

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Demo: Coloured objects undercoloured lights (optional)Red, green and blue light sourcesRoom with very good blackout

Per group:Red, green and blue filters

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5 In and register. More able pupils will supply more articulate and Starter. Q and A session. How do we see objects? How do we see coloured accurate descriptions.objects? The information on page 30 and the diagrams may help pupils visualise what is happening.

15 Development. Pupils under the heading of ‘Seeing coloured objects’ draw a Less able pupils may need some support when Pupils understand that coloured objects absorb some colours red, green, blue, white and black object. Under each diagram pupils write a writing the explanation for each diagram. of light and reflect others.sentence explaining why the object is seen to be this colour.

15 Using the Pupil Book as support pupils are asked what colour does a coloured Less able pupils will find this idea difficult and object look in coloured light. The whole class (teacher led) then works their will need lots of support, e.g. give lots more way through all the examples. If a suitable blackout is available, pupils could examples.be shown the effects of viewing coloured objects in coloured lights.

15 Plenary. Pupils are made aware of coloured pieces of plastic or glass, More able pupils may be able to predict what Pupils understand that coloured filters transmit some colours called filters, which allow only certain colours to pass through them. The happens when light tries to pass through several but absorb others.explanations and examples on page 32 of the Pupil Book will support this. filters.If plastic filters are available, pupils can be given these and encouraged to play with them to discover what light is allowed to pass through and what light is absorbed.

Homework: Pupils do question 14 on page 32 of the Pupil Book. Pupils make notes with a diagram on the action of filters.


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Lesson Focus Pupil Book 2 Chapter 2Quick revision of coloured lights, objects and filtersEnd of Unit test

ExpectationsMost Pupils Demonstrate good understanding of reflection and refraction.

Demonstrate a sound understanding of the origin of coloured lightand the appearance of coloured objects.

Less Able Pupils Demonstrate the ability to recognise examples of reflection andrefraction. Can explain simple interactions between light andcoloured objects/filters.

More Able Pupils All the above and can predict, giving clear reasoning, thebehaviour of light after striking an object.



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Worksheet B7 Coloured lightsOne per pupil


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10 In and register. More able pupils will be able to work their way Pupils are able to use the colour triangle to predict what Starter. Pupils are given Worksheet B7 Coloured lights to complete and the through the material covered on the worksheet colours will be produced when two coloured lights overlap.Pupil Book to provide material for revision. While this is taking place some and in the chapter faster and with less support. Pupils can predict the apparent colour of coloured object in consideration can be given as to where pupils will sit during their End of Unit coloured lights.test. Pupils are encouraged to ask if they are unsure of anything. Pupils can predict the effect of passing light through a

coloured filter.

5 Pupils are sat in the appropriate place, and are given instructions about the manner in which the test is to be taken and a reminder of the length of the test. The test is given out.

30 Pupils carry out the End of Unit test. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the correctly and will attempt the extension question. End of Unit test.

5 The test is stopped and collected in. Comments about behaviour in the test are always valuable, e.g. ‘Well done, I’m very pleased’, ‘You can do better that that’, ‘Not acceptable’.

Homework:


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64

UN I T

1 Place all three screens on a table and thread a piece of cotton or thinstring through each of the holes.

2 Pull the cotton tight so that the holes in all three screens are in a straightline.

3 Place a luminous object such as a light bulb or Bunsen flame behind theend screen.

4 Very carefully remove the cotton without changing the positions of thescreens.

5 Look through the hole in the screen furthest from your light source. Whatcan you see?

6 Now move one or more of the screens so that the holes are not in astraight line. What can you see now when you look through the hole inthe first screen? What does this prove?

B1 Light travels in straight

lines (page 1)

CHAPTER

WORKSHEET1

2


➤continued

screen

light source

ray oflight

65

UN I T

B1 Light travels in straight

lines (page 2)

CHAPTER

WORKSHEET1

2


7 Take a short piece of Bunsen burner tubing and pull it taut and absolutely straight.

8 Try to look at an object through the tubing. What do you see?9 Now alter the shape of the tubing so that it is curved rather than being

in a straight line.10 Try looking at an object through the tubing. What do you see? What

does this prove?11 Copy out the diagram shown below.

12 Add rays to the diagram to show how the object creates a shadow.13 Draw in the shape of the shadow.14 What assumption did you make about how light travels when you drew

your diagram?

opaque object

screen

small sourceof light


➤continued

1 Draw a line 10 cm long near the top of a piece of plain paper.2 Mark the centre of this line and, using a protractor, draw a line through

this spot which is at 90° to the first line. This line is called a normal.3 Place a plane mirror on the first line you drew so that the normal you

have drawn meets the centre of the mirror.4 Use two small pieces of plasticine to hold the mirror in place.5 Aim a single ray of light from a ray box at the point where the normal

meets the mirror.6 Mark the path of this ray by two small crosses. This ray is called the

incident ray.7 Mark the path of the reflected ray by two small crosses.

8 Using a ruler, draw in the paths of the incident ray and the reflected ray.9 Using a protractor, measure the angle between the incident ray and the

normal. This is called the angle of incidence.10 Now measure the angle between the reflected ray and the normal. This

is called the angle of reflection.

11 Repeat the experiment five more times using different angles of incidence.

(Hint: Use rays that have angles of incidence between 10° and 80°.)

UN I T

B2 Reflection of light (page 1)

CHAPTER

WORKSHEET2

2

incident ray

i = angle of incidence r = angle of reflection

mirror

reflected ray

normal

ir

plasticine

normal

single ray

ray box

plane mirror

X

XX

X

67

UN I T

B2 Reflection of light (page 2)

CHAPTER

WORKSHEET2

2


12 Record all your results in the table below.

Angle of incidence (º) Angle of reflection (º)

1 What conclusion can you draw from your experiment?2 How are rays of light reflected from curved mirrors?

Where are these mirrors used?

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B3 Periscopes and

kaleidoscopes (page 1)

CHAPTER

WORKSHEET3`

2


Part A: Making a simple periscope1 Take a thick cardboard tube with a diameter between 8 and 10 cm. Cut

two horizontal slots in your tube, one towards the top of the tube, theother towards the bottom. The slots should cut through the tube wall atan angle of 45° to the vertical and be large enough to support each ofyour mirrors.

2 Cut a hole about 3 cm indiameter below the slotnear the top of the tube sothat light entering here willstrike the mirror that isgoing to be fixed upsidedown into the upper slot.

3 At the bottom of the tubecut a second hole, again 3cm in diameter, throughwhich light can emergeafter being reflected fromboth mirrors. This holeshould be on the oppositeside of the tube to the holenear the top.

4 Slide each of your mirrorsinto the slots you have cut.The upper mirror shouldhave its silvered facepointing downwards. Thelower mirror should have its silvered face pointing upwards.

5 Fix the mirrors to the tube walls using pieces of sticky tape. Your simpleperiscope is now complete. Can you use it to look over objects and seeround corners?

6 Draw a ray diagram to show the path of a ray of light travelling throughyour periscope.

Part B: Making a simple kaleidoscope1 Use three identical rectangular mirrors. Tape two of the mirrors together

along one long edge with their mirror sides facing, as shown below formirrors A and B. Then open out mirrors A and B, and tape mirrors B and C,mirror sides together.

slots cut at 45° to hold mirror

holes cut in tube to let light enter and leave

cardboard or plastic tube

sticky tape used to hold mirror in place

tapemirror sidestogether A A

B C

B

➤continued

69

2 Now tape the edges of mirrors A and C together with the mirror surfacesfacing inwards and forming a triangle as shown below.

3 You can add more tape to secure the positions of the mirrors so that allthree angles of the triangle form 60º.

4 Cover one end of the triangular tube withtracing paper and secure it with sticky tape.

5 Put some very small pieces of colouredplastic or paper inside the tube.

6 Lift the tube up to let light through thetracing paper. Then look down the tube tosee the pattern created by yourkaleidoscope.

B3 Periscopes and

kaleidoscopes (page 2)

CHAPTER

WORKSHEET3

2


1 How does your kaleidoscope make these patterns? Explain inone or two sentences.

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tracing paperand tape

A

C

B

Tip:The more light there is coming

through, the easier it is to see

the pattern. Try using (a) pieces

of paper or plastic that are thin

and translucent so that light can

pass through them and (b) a

weak light source, placed below

the tracing paper. If you cannot

do either of these, try to leave a

gap of about 2 cm between your

eye and the open end of your

kaleidoscope when looking at

the pattern.

1 Draw a line 10 cm long in the centre of a piece of plain A4 paper.2 Place a plane mirror on this line, holding it in an upright position using

two small pieces of plasticine.3 Place an optical pin in front of the centre of the mirror and between 10

and 15 cm from it. This is the object pin.4 Mark the position of the object pin on the paper.5 You will find most of the next steps easier to do if your eye is close to the

desk top. Close one eye and look from a position to the left of the objectpin at its image in the mirror. Now place two more pins, called P1 and P2,between you and the mirror so that your eye, the two pins P1 and P2 andthe image of the object pin are all in a straight line.

6 Mark the positions of P1 and P2 on the paper.7 Repeat steps 4 and 5 using two more pins (P3 and P4) while looking at

the image from a position which is to the right of the object pin.

8 Remove all the pins and the mirror from the paper.9 Draw a line through positions P1 and P2 so that the line extends well

beyond the line marking the position of the mirror.10 Draw a line through positions P3 and P4 so that this line also extends

beyond the line marking the position of the mirror.11 The position of the image is where the lines drawn in parts 9 and 10 cross.

12 Measure the distances between the image and the mirror and the objectand the mirror. What have you discovered from this investigation?

13 If there is time, repeat the investigation to see if your conclusion isconfirmed.

70

B4 Finding the image in a

plane mirror2

CHAPTER

WORKSHEET4`


object pin P

plasticine

plane mirror

P3

P4

P2

P1

P'

plane mirror

X

XX

X

image of object

P2

P1

P3

P4

line

P

1 Place a rectangular glass block in the centre of a plain piece of paper anddraw round it with a pencil.

2 Direct a single ray of light from a ray box onto one of the longer sides ofthe block so that the ray emerges from the opposite side of the block.

3 Mark with two small crosses the path of the incident ray.4 Mark with two small crosses the path of the ray that emerges from the

block.

5 Remove the block and use a ruler to draw in the paths of the incident rayand the emerging ray.

6 Draw a line connecting the point where the incident ray enters the glassblock and the point where the ray leaves the block. This represents thepath of the refracted ray.

7 Draw in a normal (a line at 90° to the surface) at the point where the rayenters and leaves the block.

71

B5 What happens to a ray of

light as it travels through a

glass block? (page 1)

CHAPTER

WORKSHEET5

2


glass block

path of incident rayX

X

X

X

paper

ray box

normal

incident ray

normal

refracted ray

➤continued

8 Repeat the whole experiment, but this time send the ray of light into theblock at a different angle.

Try this investigation at home.You will need just a drinking mug, a small coin and a second mug filled withwater.

9 Place the small coin in the empty mug. Position your head directly abovethe mug so that you can see the coin.

10 Now slowly move your head back so that it is no longer directly over themug. Stop moving as soon as you are no longer able to see the coin.

11 Without changing the position of your head, pour water from thesecond mug into the mug containing the coin. What do you see now?Can you explain what is happening? Can you draw two ray diagramsshowing what is happening before and after you poured the water intothe mug containing the coin?

72

B5 What happens to a ray of

light as it travels through a

glass block? (page 2)

CHAPTER

WORKSHEET5

2


1 Which way does the ray bend as it enters the block?2 Which way does the ray bend as it leaves the block?

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3 Write out the following sentences and fill in the gaps usingthe words ‘away from’, ‘towards’, ‘slows down’, ‘speeds up’:

When a ray of light enters a glass block it ............. ............. and

bends ............... the normal. But when the ray leaves the block

it ............... .............. and bends ............... ............... the normal.4 Shine a single ray of light along one of the normals. What

happens to this ray?

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5 Why do swimming pools and ponds always look shallowerthan they really are?

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1 Using a compass, draw a circle with a diameter of approximately 10–15 cmon a piece of stiff white card.

2 Cut out the circle.3 With a ruler and pencil, divide the circle into eight equal parts.4 Colour seven of these parts with the colours of the rainbow. Leave the

eighth piece white.

5 Use the sharp point of a compass to maketwo small holes in the disc as shown in thediagram. The holes should each be an equaldistance (about 2 cm) from the centre of thedisc.

6 Take a piece of thick thread or thin stringapproximately 1 m long. Thread this throughone of the holes and then back through thesecond hole. Tie the two loose endstogether.

7 Put your hands inside the thread as shown inthe diagram below. Then ask your partner toturn the disc so that the thread becomes‘wound up’.

8 Release the disc and at thesame time move your handsapart, pulling gently on thethread. This should cause thedisc to spin. With a littlepractice you should be ableto keep the disc spinning byalternately pulling andslackening the thread.

9 If the disc is spinning rapidly enough the different colours will appear tomix. What colour do they make? What does this prove?

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B6 Newton’s disc: Is white light

a mixture of all the colours of

the rainbow?

CHAPTER

WORKSHEET6

2


Red

Blue

Yellow Indigo

Orange

White

Green

Violet

Mixing coloured lightsThe diagram below shows three coloured, overlapping lights. Using thecolour triangle work out the colours of the areas marked A, B, C and D.

Coloured objects in coloured lightsUse the colour triangle to fill in the empty spaces in your table.

74

B7 Coloured lights (page 1)

CHAPTER

WORKSHEET7

2

True colour Colour of light Apparent colour of object shone on object of object

blue green

red blue

green green

blue white

magenta red

yellow green

cyan magenta

cyan red

white yellow

white cyan

yellow cyan

magenta yellow


red greenA

C

DB

blue

➤continued

Coloured filtersLook at the table below. Decide which colour(s) of light can travel through(a) filter A and (b) both filters. If no light can pass through a filter, write theword None.

75

B7 Coloured lights (page 2)

CHAPTER

WORKSHEET7

2

Colour of Colour of Colour of light Colour of Colour of lightlight filter A able to pass filter B able to pass

through filter A through both filterswhite green green

white blue red

white yellow red

white cyan blue

white magenta yellow

yellow red red

yellow green blue

magenta cyan blue

magenta yellow cyan

cyan blue green

filter Bfilter Abeam oflight



1 An astronaut looks at the Sun (through dark safety glasses) from the Earthbefore travelling from Earth in a direction away from the Sun to the distantplanet Pluto. When the astronaut now looks at the Sun its appearance isdifferent. Describe two ways in which the appearance of the Sun has changed.

..............................................................................................................................

..............................................................................................................................

(2)

2 Explain why there is no delay between turning on a light bulb and seeing thelight it emits.

..............................................................................................................................

..............................................................................................................................

(1)

3 Why are we unable to see objects if we close our eyes?

..............................................................................................................................

..............................................................................................................................

(1)

4 Explain the difference between a luminous object and a non-luminous object.

..............................................................................................................................

..............................................................................................................................

(2)

5 Explain the difference between an opaque object and a transparent object.

..............................................................................................................................

..............................................................................................................................

(3)

End of Unit test

Light

CHAPTER

2

77

6 The diagram below shows a ray of light striking a plane mirror.

a At what angle to the mirror will the ray be reflected?

.........................................................................................................................

(1)b What is the angle of reflection for the above ray?

.........................................................................................................................

(1)

7 A pupil who is 1.5 m tall stands 2 m from a plane mirror.

a How tall is the image of the pupil created by the mirror?

.........................................................................................................................

(1)b How far behind the mirror is the image of the pupil formed?

.........................................................................................................................

(1)

8 The diagram below shows a ray of light striking the top surface of a glassblock. Using a pencil and ruler, show the path the ray follows in the blockand as it emerges from the lower surface.

(2)



30º

mirror

glass block


9 The diagram below shows two prisms and a ray of white light.

a What happens to the ray of light as it enters and leaves prism A?

.........................................................................................................................

(1)b What happens to this light as it enters and leaves prism B?

.........................................................................................................................

(1)c What does this simple experiment show?

.........................................................................................................................

(1)

10 Using the colour triangle below, work out the colours of the areas marked A, B and C.

a A is ………………………………… (1)

b B is ………………………………… (1)

c C is ………………………………… (1)

whitelight

A

B

red

red

green

greencyan

B

CA

blue

blue

yellowmagenta



11 Explain why a red car looks red in white light.

.........................................................................................................................

.........................................................................................................................

(2)12 Look at the diagram below and explain what happens to the white light

as it strikes the blue filter. Use the words transmitted and absorbed in your answer.

.........................................................................................................................

.........................................................................................................................

(2)

Total marks: 25

Extension question

13 Light waves travel at 300 000 kilometres per second. Calculate how long it would take light to travel from the edge of the Solar System to the Earth, a distance of 6000 million kilometres.

.........................................................................................................................

.........................................................................................................................

(3)



white light

blue filter


Text answers1 The Sun will appear smaller and not so bright.2 The Sun will appear bigger and brighter.3 a 85 minutes b 4 minutes and 15 seconds4 Examples of luminous objects – fire, light bulb, lamp, star, Sun

Examples of non-luminous objects – table, door, wall, ceiling, pupil, teacher

5

6 There is no light to enter your eye.7 a Examples of transparent materials include plain glass, some plastics,

clear liquids, e.g. water. Uses include windows, screens, lenses in optical instruments, glasses, filters.

b Examples of opaque materials include wood, all metals, concrete, some plastics. Uses include window blinds, parasols, walls, ceilings, floors.

c Examples of translucent materials include frosted glass, tracing paper, some plastics, some liquids, some fabrics. Uses include toilets and bathrooms, glazed doors, lampshades.

8 Ray of light strikes surface at 30° and is reflected so that the angle between the reflected ray and the mirror is also 30°. The two angles are marked with their values.

9 Answers will vary.10

LightC

HAPTER

2

ANSWERS

30º 30º

luminous object

reading lamp

non-luminousobject

glass block


11

12 Red, orange, yellow, green, blue, indigo, violet13

14

15

Literacy activity answersa Compact discb Thousands of small bumps with flat bits in between themc A laserd A photodiodee A code consisting of a stream of numbers, in this case a series of ones

and zerosf A large amount of information/music can be stored in a small space. There is

no wear and tear on the surface due to playing. The sound quality andaccuracy of a CD are superior to other methods of recording and replaying


red red redgreen blue blackblue red blackmagenta green blackyellow magenta red

Colour A Colour B Colour A + Colour Bred green yellowgreen blue cyanblue red magentamagenta green whiteyellow blue white

Chapter 2 Answers

Colour of Colour of Colour of Colour(s) of lightlight filter A filter B able to pass

through both filterswhite red red redwhite blue blue bluewhite red green nonewhite green blue nonewhite magenta yellow redwhite cyan yellow greenyellow yellow red redyellow magenta red red

glass block

undeviated ray


End of chapter answers1 see, luminous, light, non-luminous, reflects, eyes, opaque, transparent2

The angles through which the rays have turned are (a) 60°, (b) 90° and (c) 120°.

3 Surface A is flat and so reflects all the rays in the same direction. Lots of raystherefore enter the eyes of the observer, so the surface appears shiny.Surface B is not flat and so reflects the rays in all directions. Not so manyrays now enter the eyes of the observer, so the surface appears dull.

4 a So that drivers can read the writing when they see it in their rear view mirrors.

b Answers will vary.5 a 1.5 m b Red c 2 m d 4 m

e What is on the right hand side of the girl appears to be on the left hand side of her image.

6 Light reflected from the fish changes direction as it crosses the water/airboundary. Therefore the fish appears to be in a position where it is not, i.e.it appears to be a little shallower in the water and further in front of theboat.

7 The three guns produce red, green and blue colours on the TV screen. Theseare the three primary colours for light and any other colour can be made bymixing these colours in different proportions.

8 Being colour blind means being unable to distinguish the differencebetween certain colours, i.e. they seem to be the same. This is tested usingcolour-blind testing books. Wiring plugs, traffic signals, etc.

Worksheet answersB1 Light travels in straight lines

Step 14: it is assumed that light travels in straight lines.

B2 Reflection of light1 A ray of light is reflected from a plane mirror such that its angle of incidence

is equal to its angle of reflection.2 There are two main types of curved mirrors. Concave mirrors reflect rays so

that they converge. A shaving mirror or make-up mirror is concave. Convexmirrors reflect rays so that they diverge. Rear-view driving mirrors and themirrors on the stairs of double-decker buses are convex mirrors.

B3 Periscopes and kaleidoscopes1 Each mirror of the kaleidoscope is creating its own image of the coloured

shapes. These images are then creating more images in the other twomirrors.

B4 Finding the image in a plane mirrorStep 12: the image is as far behind the mirror as the object is in front.

30º 30º 60º 60º45º 45º

a b c

Chapter 2 Answers

83

B5 What happens to a ray of light as it travels through a glass block?1 Towards the normal2 Away from the normal3 When a ray of light enters a glass block it slows down and bends towards

the normal. But when the ray leaves the block it speeds up and bends away from the normal.

4 The ray passes through the block without being refracted, i.e. it is undeviated.

Step 11: it is possible to see the coin now because when rays of light emergefrom the water they are refracted away from the normal.5 Refraction creates a false image (virtual image) higher in the water than

the actual bottom of the pond or swimming pool.

B6 Newton’s disc: Is white light a mixture of all the colours of the rainbow?Step 9: the spinning colours merge to produce a whitish colour. (Somecolours on the disc may be more vivid than others and therefore give thedisc a tinge of that colour.) This proves that white light is a mixture ofcoloured lights.

B7 Coloured lightsA yellow, B magenta, C white and D cyan

Hint: Find the common colour between the light shone on the object andthe object’s own colour. This is the colour which is reflected. If there is nocommon colour then no light is reflected and the object will appear to be black.


Chapter 2 Answers


blue green blackred blue blackgreen green greenblue white bluemagenta red redyellow green greencyan magenta bluecyan red blackwhite yellow yellowwhite cyan cyanyellow cyan greenmagenta yellow red

84

End of Unit test answers1 The Sun will appear to be smaller and less bright. (2)2 Light travels very quickly or delay so small it is not noticeable. (1)3 Because no light is able to enter our eyes. (1)4 A luminous object gives off or emits light; a non-luminous object does not/it

only reflects light. (2)5 Rays of light cannot pass through an opaque object/we cannot see through it.

(1)Rays of light can travel through a transparent object/we can see through it.(2)

6 a 30° (1)b 60° (1)

7 a 1.5 m (1)b 2 m (1)

8 Ray drawn so that it bends towards normal as it enters the block. (1)Ray drawn so that it bends away from the normal as it leaves the block. (1)(See third diagram on page 27 in the Pupil Book.)

9 a White light splits up or is dispersed or is refracted causing the different colours to travel in slightly different directions. (1)

b The coloured lights converge and recombine/make white light. (1)c White light is a mixture of coloured lights. (1)

10 a Magentab Cyanc Yellow (3)

11 When the white light strikes the red car all the colours are absorbed except for red. (1) The red light is reflected and so the car looks red. (1)

12 All of the colours are absorbed except for blue which is transmitted through the filter. (2)

Total marks: 25

Extension answer13 Time = distance/speed = 6 000 000 000 km/300 000 km/s = 20 000 s or 333

min or 5 hours 33 minutes.





Colour of Colour of Colour of light Colour of Colour of lightlight filter A able to pass filter B able to pass

through filter A through both filterswhite green green green greenwhite blue blue red nonewhite yellow yellow red redwhite cyan cyan blue bluewhite magenta magenta yellow redyellow red red red redyellow green green blue nonemagenta cyan blue blue bluemagenta yellow red cyan nonecyan blue blue green none

Chapter 2 Answers

Pupils should be familiar with the following ideas:• Food is needed for activity and growth, and that an adequate and varied diet is

needed to maintain health• Matter, including food, consists of particles which can differ in size• Recognise that food provides energy for the body

3 Food and digestion

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AbsorptionAlimentary canalAmylaseAnusBalanced dietBenedict's solution

Biuret solutionCarbohydrates

CarnivoreCatalystDigestionEnzymesFaecesFatsFibreHerbivoreIodine solution

LipaseLiverMineralsNutrientsOmnivorePancreasProteaseProteinsSaliva

Small intestineStarchStomachSugarVitaminsWater

In this topic pupils should learn:• about different foods and how they can combine to produce a balanced diet• how food is broken down by digestion so that it can be used by the body, for

energy, growth and repair• how to use a model to explore digestion• how to use chemical tests to identify food types• how to present and interpret data from secondary sources• how to draw conclusions from observations and explain these using scientific

knowledge• how to investigate a question about nutrition using secondary sources of

information

Learning checklist

Links

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Unit Title5A Keeping Healthy


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Cross-curricular linksUnit 8A (i) Exploring Materials (Food) and unit 9A (i) Selecting Materials (food)in the design and technology scheme of work.

LiteracyThere is a literacy exercise entitled ‘Why rabbits can eat grass’ in the Pupil Book.

NumeracyThe chapter contains many calculations involving the nutrients contained in foodin both the Pupil Book and the Worksheets.

ICTWorksheet C3, Which foods are good sources of nutrients? could be extended byrecording the data collected into a spreadsheet.


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Scientific enquiry• Use secondary sources of information to generate graphs or displays relevant to

questions asked• Recognise that interpretation of evidence about questions of health and diet may

be difficult • Identify and control relevant variables when investigating the action of an enzymeLife processes and living things• Name nutrients, fibre and water as part of a balanced diet, identifying examples

of foods in which they are found, and describe the role of the main nutrients inthe body

• Use a model to describe how large molecules are broken down during digestion


Scientific enquiry• Find information from selected secondary sources about food and diet; generate

graphs or displays relevant to questions asked• With help, control relevant variables when investigating the action of an enzymeLife processes and living things• Name some groups of nutrients and identify some examples of foods in which

they are found• Describe a balanced diet

Learning outcomes



Unit Title7A Cells 7G Particle Model of Solids, Liquids and Gases7I Energy Resources8B Respiration8F Compounds and Mixtures9B Fit and Healthy


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Most pupils will already have learnt something about food and diet. The termnutrient is likely to be new to many of them. It is recommended that you usethis term whenever you are talking about the types of food in a diet (proteins,carbohydrates, etc.) and use the term 'food' for what we actually eat (bread,milk, etc.).

FoodPupils will probably be able to tell you that we need food for energy and for‘body-building’. This could be an opportunity to discuss and revise Year 7 workon energy, reminding pupils about the units in which it is measured (joules, J),why we need energy, and how energy passes along food chains. You could alsodiscuss what actually happens when a body grows or repairs itself, which willinvolve revising Year 7 work on cells and tissues.

What is in food?A label from a breakfast cereal packet is used to introduce the main nutrientsfound in food. It is suggested that you don’t go into detail about the differentminerals and vitamins here; this can be revisited in Year 9 Fit and Healthy.Similarly, although saturated and unsaturated fats will need to be mentioned(because they appear on food labels), there is no need to go into any detail atthis stage.

In order to understand the information on the food label, pupils will need tothink about the relationship between grams and milligrams. It would be helpfulto show them what 100 g of food looks like.

You may also like to help pupils to analyse the nutrients present in a meal, asdescribed in Lesson Plan 1. Using a computer program is much the mostrewarding method of doing this, but failing that, Chapter 3 Information sheetprovides information for some typical foods that pupils might eat for theirmidday meal. You could add data for other nutrients if you think this will benecessary. Make sure that foods from a wide range of diets are included.

Finding out what is in foodWorksheet C1,Testing foods for protein and fat, and Worksheet C2, Testing foodsfor starch and sugar, provide opportunities for pupils to test a range of foods forthese nutrients. In each case, provide a range of foods of both plant and animalorigin. It is probably best to avoid foods which contain nuts, as these may causedangerous allergic reactions in some pupils.

Encourage pupils to record the actual colour or appearance that they obtain aftertesting a food, not just ‘no change’. Help them to understand the difference



Scientific enquiry• Choose secondary sources to provide the information needed about food and

diet• Explain why interpretation of evidence about questions of health and diet may

be difficultLife processes and living things• Explain why some nutrients have to be broken down before they can be used

by the body, and why some foods cannot be digested by humans


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between their results (what they see) and their conclusions (their decisions aboutwhether a particular nutrient is present or not).

The Benedict’s test for reducing sugar is the only one where heating is required.Much the best way of doing this is to stand tubes in a very hot water bath; itdoes not need to be boiling. Indeed, prolonged boiling will break down starchand sucrose to reducing sugars, and give a false positive result. Note that sucrose(the sugar normally used in cooking, and to sweeten coffee and tea) is not areducing sugar, and does not give a positive result with the Benedict’s test.

Worksheet C3, Which foods are good sources of nutrients?, involves analysinglabels from a range of food products. Most pupils will probably be able to findthese themselves, but you may need to provide some as well. Try to include agood range of the following: tin of tuna, tin of baked beans, carton of milk, packof cheese, carton of fruit juice, bottle of fizzy drink, loaf of bread, pack of mince,pack of tomatoes, pack of oranges, pack of a green vegetable, bar of chocolate,pack of potatoes, pack of margarine, tin or pack of chick peas (or other legume).

Safety: Take care with possible health hazards from dirty labels from, e.g.,packs of fresh meat products.

It will not be an easy matter to pick out patterns from the wealth of informationcollected, and it is therefore suggested that you lead this as a class activity. Aninteractive white board would be invaluable here.

In general, expect to find that:

• foods from animals tend to contain more protein than foods from plants• foods from animals tend not to contain vitamin C• foods from animals tend to contain less carbohydrate than foods from

plants, and never contain starch• foods from plants contain more fibre than foods from animals• foods from plants tend to contain more unsaturated fat and less saturated

fat than foods from animals.

However, these differences may be difficult to pick out if the foods have beenprocessed, as this can involve adding other nutrients to them.

A balanced dietSome pupils may associate ‘diet’ with a weight-reduction diet, so try to make itsreal meaning clear at an early stage. Be aware of the sensitivity of overweightand underweight children when discussing diets, or any who have a particulardiet for medical reasons. Try to make positive statements rather than negativeones – concentrate on what people should eat rather than what they should noteat. For example, in many people's minds, ‘fat’ in a diet is a bad thing; yet fathas many positive uses in the body and is an essential part of a balanced diet. Asensible and positive stance to take is that a balanced diet contains a wide rangeof foods, contains some – but not too much – of all the main nutrients, and isinteresting and enjoyable to eat.

Pupils might be interested in the nutrient content of so-called ‘junk foods’. Arethey really worthless in a diet? The answer, of course, is that they do haveconsiderable food value, and there is no reason why burgers and fries, fizzydrinks and crisps cannot form part of a balanced diet. But they should not be thebackbone of the diet, and should not be eaten in excess, because they containlarge amounts of saturated fats and sugar which can be harmful if eaten in largequantities, and because they are lacking in several vitamins and minerals.

There are many interesting aspects of diet that could be investigated, and youmight like to organise groups of pupils to research one topic of their choice. There


!



are suggestions in the homework for Lesson Plan 4, and others in End of chapterquestion 5 in Chapter 3 of the Pupil Book. Each group could give a short (3–4minute) presentation to the class on their findings.

Digestion and the alimentary canalIt is not unusual to find pupils, even at AS level, who think that food goes allover the body – through liver, pancreas, kidneys and practically everywhere else –after it has been eaten. Try to help pupils to think of the alimentary canal as ahollow tube whose contents are actually part of ‘the outside world’, not reallypart of the body at all. Models may be helpful here.

Worksheet C4, Absorbing carbohydrates, investigates which kinds ofcarbohydrates have molecules small enough to be absorbed. Pupils should findthat the starch all stays inside the Visking tubing, while the sugar diffuses out. It isimportant to use glucose as the sugar, as disaccharides such as sucrose or maltosedo not easily pass through the tubing – their molecules are too big. Pupils willneed to think about the sugar, starch and water in terms of particles, so this is agood opportunity to reinforce their understanding of particle theory.

They could be encouraged to think of the Visking tubing as a ‘model alimentarycanal’ – the tubing represents the walls of the canal, with the ‘meal’ inside andthe water outside representing blood.

What happens to nutrients with large molecules?In order to understand digestion, pupils need to be able to use the term moleculewith confidence. They really do need to use the term molecule in this context,not just ‘particle’, which conjures up visual images of crumbs of bread or drops ofmilk. You can use simple models – for example, popper beads linked in a string –to represent the large molecules of proteins, starches and fats, and how these are‘digested’ by being broken down into individual beads. (This isn't really true offat molecules, but it is probably best not to make things any more complicated atthis stage.)

Analogies may also be helpful in visualising relative sizes. If a body cell were onemillion times larger it would be the size of a 10 m square room. On the samescale, a starch molecule would be like a marble, and a sugar molecule about thewidth of two full stops.

How digestion happensEnzymes are introduced here, as biological catalysts. One common error is forpupils to think that all enzymes help in digestion, so it may be worth pointingout that most enzymes don't do this. Another common mistake is to believe thatall catalysts are enzymes. This is probably the first time that pupils will have metthe idea of catalysts, so you may need to spend a little time on this idea.

Worksheet C5, Digesting starch, investigates the effect of amylase on starch. Youcould use pupils’ own saliva, rather than amylase powder, if you prefer. However,spitting into test tubes does not appeal to every pupil, and watching other peopledoing it is even less appealing. If you do decide to do this, then each pupil mustuse their own saliva. Glassware should be plunged into disinfectant immediatelyafter use, and benches wiped down with disinfectant.

Amylase from different sources behaves differently, and it is very important thatyou trial appropriate concentrations of amylase and starch beforehand. Try 0.1%amylase and 1% starch to begin with – you are aiming for complete digestion ofthe starch within about 5 or 10 minutes maximum, but in not less than about 2minutes, using equal volumes of enzyme and substrate solution. Adjustconcentrations to achieve this.



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Enzymes, temperature and pHWorksheet C6, How does temperature affect starch digestion?, looks at the effect ofexposure to different temperatures on the activity of amylase. If you use saliva asa source of amylase, the optimum temperature is likely to be around 40 °C.Bought amylase powder is likely to have come from fungi, and is likely to havean optimum much higher than this, perhaps around 60 °C or even higher. Pupilsshould understand that not all enzymes work best at human body temperature.

If your class is progressing well, you might prefer to present this investigation as aplanning exercise, rather than giving the worksheet to the pupils.

As an alternative or addition to this investigation, you could ask pupils to carryout the investigation on Worksheet C7, How do teeth help with digestion? Theycould use bread or a biscuit as the substrate, and compare the rate ofdisappearance of starch when the food is in large or small pieces.

The digestive systemThis is treated very simply. The important thing to understand is that food passesthrough a hollow tube from the mouth to the anus; along the way, largemolecules are broken down to small ones (in the mouth, stomach and smallintestine) which are then absorbed into the blood (in the small intestine).However, most pupils will be able to learn the names of the main parts of thealimentary canal, and know in which parts digestion and absorption take place.

It is suggested that, at this stage, you do not move on to consider what happensto the different types of food after they have been absorbed. The role of theblood system in transporting absorbed food around the body, and the use ofcarbohydrates in respiration, are introduced in Chapter 5.


Worksheet C1 Testing foods for protein and fat

Testing for proteinTry to ensure that the foods to be tested cover a range of those that you knowwill contain detectable quantities of protein (meat, milk, fish, cheese, beans) andsome that will not (fresh fruit, sweets). Bread contains surprisingly large amounts.Cheese gives an excellent positive result with the biuret test.

Some pupils will find it difficult to tell the difference between the coloursindicating positive (mauve, lilac, purple) and negative (blue) results. It is a goodidea to carry out the test on water and on a protein solution (for examplealbumin) and stand these tubes where they are visible and can be used by pupilsas references against which they can compare their own results.

An alternative to using ready-made biuret solution is to use a 20% potassiumhydroxide solution (care – this is caustic) and a 1% copper sulfate solution. TheKOH is added to a suspension of the food to be tested and mixed with it, afterwhich a little CuSO4 solution is added. The results are the same as those describedon Worksheet C1.

Testing for fatThe test described here is sometimes called ‘the ethanol test’ and sometimes ‘theemulsion test’. It works because fat is soluble in ethanol but not in water. Whenethanol is shaken with the food, fat will dissolve into it. If this solution of fat inethanol is then mixed with water, some of the fat forms tiny droplets in the water(an emulsion) which produces the milky appearance.




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This test is less easy to carry out effectively than the biuret test, so be prepared forsome unexpected results! Some fats do not readily go into solution in ethanol,especially at low temperatures. Dirty test tubes and dirty fingers can confuseresults. Another problem is that some foods easily suspend in alcohol (even if theydon't dissolve) and if this suspension is transferred to the water it can look a littlelike a positive result. A very concentrated ethanol solution – it should really beabsolute ethanol – is ideally required, and this is expensive. In the light of all this,you may prefer to demonstrate this test rather than ask pupils to carry it out forthemselves.

Worksheet C2 Testing foods for starch and sugar

Testing for starchThis test is very reliable, and is usually the one that all pupils always remember.Iodine solution is not harmful, but it does stain skin and clothes, so warn pupilsabout this. Protective clothing (an old shirt at the very least) is advisable.

Testing for sugarThis is the only one of the food tests which requires heating, and it is stronglyrecommended that you use a water bath rather than heating directly over aBunsen flame. The liquid does not need to boil, but only to reach a temperatureabove about 80 °C. If foods containing starch but not sugar are boiled for severalminutes, then the starch may begin to break down to sugar and give a falsepositive result.

Sucrose does not give a positive result with the Benedict’s test. This may producesome surprising results, although it seems that most foods containing sucrose doalso contain enough other sugars (such as glucose or fructose) to give a positiveresult.

Worksheet C4 Absorbing carbohydrates

Although this seems on the face of it to be quite a simple investigation, theinterpretation of its results requires the synthesis of a number of ideas. You maylike to spend a little time introducing this by:

• checking that all pupils have at least a basic understanding of what a ‘molecule’is;

• encouraging them to think about the mixture of water, starch and sugar insidethe Visking tubing in terms of the three different kinds of molecules/particles;try to make sure that they think about the individual particles of sugar andwater rather than of ‘sugar solution’ as a single entity;

• reminding them about how to carry out the starch and sugar tests.

All pupils find it difficult to pull together so many ideas simultaneously, and lessable pupils may need a great deal of help to be able to predict what the resultsmay be, and to interpret the results that they obtain.

You could use questioning to encourage more able pupils to appreciate that theyshould really test the liquids both inside and outside the Visking tubing for starchand sugar in order to get a more complete picture of what has been taking place.

It is very important to submerge the Visking tubing in only a small volume ofwater, so that the glucose which passes through it forms a relatively concentratedsolution in a relatively short period of time, and is readily detectable with theBenedict’s test.



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Worksheet C5 Digesting starch

Like the previous investigation, this is very simple on the surface, but can presentdifficulties of understanding to many pupils. Less able pupils (and even some ofthe usually more able) may find it difficult to connect the results they see on thewhite tile when testing with iodine, with what is happening inside the test tube.Unfortunately, there is no visible evidence of any reaction taking place inside thetube to help them with this. Be prepared to spend a little time helping pupils tounderstand and interpret their results.

Worksheet C6 How does temperature affect starch digestion?

This requires excellent organisational skills from pupils. They need to have a goodidea of what they are going to do before they start, or everything will rapidly getout of control and they will miss collecting some results. Once again,interpretation of results is not as easy as it may look at first sight, and manypupils will need considerable help with this.

Worksheet C7 How do teeth help with digestion?

You could introduce this planning exercise by questioning pupils about how theyuse their teeth when they are eating. Pose the question: Why do we chew ourfood? You may be lucky and have a few pupils in the class who can relate this tothe need for digestion and the activity of enzymes, but you will probably have toprovide a lead for them to arrive at this point.

Their experiments can use the same basic apparatus and techniques as inWorksheet C5, Digesting starch. They will need to vary the particle size of theirchosen substrate, and to keep its mass constant, as well as keeping constant thevolume of the water they add to it, the volume and concentration of the enzymesolution, and the temperature. They could test samples at regular time intervalsas described in Worksheet C6, How does temperature affect starch digestion?



Sc1

Scientific Enquiry

1b, 2a, 2b, 2h,2i, 2j, 2m

Sc2


2a, 2b, 2c, 2d

Sc3


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Physical Processes


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What I have learnt

Food and digestion


Small intestine

Balanced diet

Stomach

Digestion

Enzymes

Fats

Vitamins

Fibre

Anus

Carbohydrates

Herbivore

Pancreas

Alimentary canal

Iodine solution

Biuret solution

Lipase

Faeces

Absorption

Starch

Liver

Minerals

Amylase

Nutrients

Omnivore

Catalyst

Protease

Benedict's solution

Proteins

Saliva

Carnivore

Sugar

Water


• I know that food contains manydifferent nutrients and I can list them

• I know why we need all of thesedifferent substances in a balanceddiet

• I can name some examples of foodswhich are good sources of each ofthese substances

• I know how to test foods for protein,fat, sugar and starch

• I know what digestion is and why itis necessary

• I know how enzymes help with thedigestion of starch, protein and fat

• I know how the activity of enzymesis affected by temperature and pH

• I know why sugar, vitamins andminerals do not need to be digested

• I know the names of the main partsof the digestive system

• I know the parts of the digestivesystem where digestion happens,and where absorption happens

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Lesson Focus Pupil Book 2 pp. 38–39The main groups of nutrients and why we need themAnalysing the nutrients present in a meal

ExpectationsMost Pupils Know that foods contain different nutrients – protein, fat,

carbohydrate, vitamins, minerals and water – and also fibre. Know that we need proteins for growth and repair, and fats andcarbohydrates for energy. Can use computer software or datasheets to find out what nutrients are present in a meal.

Less Able Pupils Know that foods contain different nutrients, and that we needthese to supply energy and for growth and repair. Can usecomputer software or data sheets to find out what nutrients arepresent in a meal.

More Able Pupils All of the above, plus can use computer software or data sheets tofind out how much of each type of nutrient is present in a meal.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: More able pupils: calculating quantities of nutrients present in a meal.ICT: Using software to investigate nutrient content of a meal.


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Demo: Groups of nutrients and whywe need themFood label on Pupil Book page 38A few samples of 100 g of differentfoods, including a breakfast cereal

The nutrients a meal containsComputers and software and/or Chapter 3 Information sheet (modifiedif required)

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10 In and register. More able pupils are likely to remember KS2 and Pupils reinforce their understanding of food being needed for Starter. Introduce the topic of food. Conduct Q and A with the class about what Year 7 work and volunteer information. growth and to provide energy, and can use the term nutrient food contains, and why we need food. correctly.

10 Development. Introduce the food label on Pupil Book page 38. Show pupils Pupils understand that food contains different nutrients which what 100 g of breakfast cereal and of other foods looks like. Discuss the have different uses in the body.different groups of nutrients and why we need them.

20 Ask pupils to write down in their workbooks what they think they will have More able pupils should be encouraged to analyse Pupils know the nutrients present in some different foods.(or what they have had) for lunch. Use computer software, the Chapter 3 a meal quantitatively. Less able pupils can Information sheet and other data sheets or other references, to find out what concentrate on listing the nutrients present in nutrients this meal contains. different foods.

10 Plenary. Discuss pupils’ meals – do they contain all the different types of Pupils can give examples of meals that provide a good range nutrients? What kinds of food should they add to their meal to improve it? of nutrients.Try to agree on a general description of a ‘good meal’. Set homework.

Homework: Answer questions 1 and 2, Pupil Book page 39. Collect some food labels (pupils should retain labels through to Lesson 4). Collect a few samples of foods to bring to the next lesson (for examples, see Lesson Plan 2, Equipment & resources needed).


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Lesson Focus Pupil Book 2 p. 40Testing foods for protein and fat

Expectations

Most Pupils Carry out tests for protein and fat on several different foods.Know a range of foods which are good sources of protein and fat.

Less Able Pupils Carry out tests for protein and fat on at least two foods.Know some examples of foods which are good sources of proteinand fat.

More Able Pupils All the above, plus use the results of tests for protein and fat toestimate the relative amounts of these nutrients in different foods.




Worksheet C1 Testing foods forprotein and fatPer group:At least 5 different food samplesincluding meat, tinned fish, cheese, freshfruit, bread. (For Lesson 1 homework,pupils were asked to bring their own, butprovide extras) Knife to cut food into small piecesClean dropper pipette (for milk or otherliquid foods) Several clean test tubes in a rackBiuret reagent and dropper pipetteEthanol Clean glass rodGoggles

Worksheet C3 Which foods are goodsources of nutrients?Chart C3 Nutrients in foods One copy of each per pupil, forhomeworkSamples of food labels (have spares incase pupils didn’t collect their own forLesson 1 homework)

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10 In and register.Starter. As a class, look through and discuss Worksheet C1 Testing foods for protein and fat. Development. Demonstrate how to carry out these tests, pointing out the appearance of positive and negative results. Emphasise the following safety points: take care with blades; protect eyes with goggles; do not taste food samples.Explain how to record results and conclusions.

25 Check that groups have suitable food samples, then direct them to test the More able pupils can be encouraged to estimate Pupils can carry out tests for protein and fat. They understand samples for protein and for fat, using Worksheet C1. Support pupils as the relative amounts of protein and fat in each the distinction between observations and conclusions.they work. food type.

5 Instruct pupils to tidy up and to wash their hands thoroughly, then to settle.

10 Plenary. Discuss group findings with the class. Which foods contained a lot Pupils know examples of foods rich in protein and fat.of protein? Which contained a lot of fat?Set homework, distributing the sheets listed.

Homework: Use the food labels you have collected to do Worksheet C3 Which foods are good sources of nutrients? and to start filling in Chart C3 Nutrients in foods. (Distribute labels to pupils with insufficient or no labels.) Bring some samples of foods to test next lesson (for examples, see Lesson Plan 3, Equipment & resources needed).


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Lesson Focus Pupil Book 2 p. 40Testing foods for starch and sugar

ExpectationsMost Pupils Carry out tests for starch and sugar on several different foods.

Know a range of examples of foods which are good sources of starchand sugar.

Less Able Pupils Carry out tests for starch and sugar on at least two different foods.Know some examples of foods which are good sources of starch andsugar.

More Able Pupils All the above, plus use the results of the tests to estimate the relativeamounts of starch and sugar in different foods, or use the starch testto investigate the distribution of starch in different parts of a fruit.




Worksheet C2 Testing foods for starchand sugarPer group:At least 5 different food samples,including milk, meat, bread, biscuit, freshfruit including an apple, cheese, raisins,potato. (For Lesson 2 homework, pupilswere asked to bring their own, butprovide extras)Knife to cut food into small piecesClean dropper pipetteSeveral clean test tubes in a rackWater bath set at close to boiling point,with racks to hold test tubesWhite tileReagents: For starch, iodine in KIsolution, in small bottles with droppers;for sugar, Benedict's solution

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10 In and register.Starter. With the class, look through and discuss Worksheet C2 Testing foods for starch and sugar.Development. Demonstrate how to carry out these tests, pointing out theappearance of positive and negative results. Remind the class of safety pointsfrom Lesson 2, and tell pupils to take extra care with very hot water in the water bath.

25 Instruct groups to test their food samples for starch and sugar, using More able pupils can be encouraged to estimate Pupils have carried out tests for starch and protein. Worksheet C2. Support pupils as they work. the relative amounts of protein and fat in each

food type.They could test different parts of a food for different nutrients, for example, they can test apple skin, flesh and pips for starch.

5 Instruct pupils to tidy up and to wash their hands thoroughly, then to settle.

10 Plenary. As a class, discuss group findings, asking: Which foods contained a lot Pupils can name examples of foods rich in starch and sugar.of starch? Which contained a lot of sugar?Set homework.

Homework: Continue to do Worksheet C3 Which foods are good sources of nutrients? and to fill in Chart C3 Nutrients in foods. Any pupils who have already finished this can begin work on researching a topicrelating to diet (see Lesson Plan 4).


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Lesson Focus Pupil Book 2 pp. 41–42What types of foods should be present in a healthy diet?

ExpectationsMost Pupils See a pattern in a complex set of data.

Understand that foods from plants contain a different balance ofnutrients from foods from animals, for example plant foods containsugar and starch. Can read and understand food labels.

Less Able Pupils Understand that foods from plants contain a different balance ofnutrients from foods from animals.Can pick out some useful information from food labels.

More Able Pupils All the above, plus see several different patterns in a complex setof data.




Food labels Pupils should have their own fromprevious lessons, but spares should beavailableWorksheet C3 Which foods are goodsources of nutrients?Used in Lesson 2, but spare copies maybe neededChart C3 Nutrients in foodsTransparency of the chart and an OHP; orinteractive white board for data display

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5 In and register. Starter. Ask pupils to look out their copies of Worksheet C3 and Chart C3 Nutrients in foods. Provide spares for any pupil who does not have one.

20 Put the transparency of the chart on the OHP or set up an interactive white More able pupils will have completed their chart Pupils can research and record information about nutrients board to display the chart. and will be able to volunteer information. present in different foods. Using Q and A, go through the column 1entries and explain them where Less able pupils can use the information provided They are becoming familiar with the terminology used on necessary (no need for detail on minerals and vitamins at this stage). to fill in their charts. food labels.Development. Ask pupils to volunteer information about one food from plants. Fill in results on the chart for at least four foods in this group.Repeat for the other two groups of foods.

10 As a class, discuss findings. Ask: What patterns can be seen? How can More able pupils will see patterns in the data, Pupils recognise patterns in data. They understand that food vegetarians make sure they get all the nutrients they need? for example that food from plants contains more from plants tends to contain different kinds of nutrients from

sugars and starch than food from animals. the kinds in food from animals.Less able pupils will need more help to pick out patterns.

15 Answer question 4 on page 42 in the Pupil Book.Set homework, providing a choice of questions for pupils to research.

Homework: Find out about a particular topic, for example: Is too much salt in the diet harmful? How does the diet of someone from one culture differ from the diet of another culture? What does a pregnant woman need in her diet? Alternatively, choose one of the topics from question 5 on page 50 in the Pupil Book, and prepare a 3–4 minute group presentation on this (to be continued in Lesson 5 homework, and delivered in Lessons 7 and 8).


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Lesson Focus Pupil Book 2 pp. 42–45Introduction to the alimentary canalAbsorption in relation to particle size



Worksheet C4 AbsorbingcarbohydratesPer group:A piece of Visking tubing roughly 90–100 mm long (diameter not important)Access to starch suspension(concentration not important) and toconcentrated glucose solution (preciseconcentration not important)Two clean dropper pipettesA small beaker into which the Viskingtubing can be placed (see diagram onWorksheet C4)Cotton for tying the tubingReagents: for testing for starch and sugaras in Lesson 3 (No knife or food samples required)

ExpectationsMost Pupils Understand that the alimentary canal is a continuous tube along

which food passes, from where it is absorbed into the blood.Understand that starch molecules are made of many sugarmolecules. Use Visking tubing as a model alimentary canal toinvestigate the absorption of sugar, and interpret the results interms of particle size and diffusion.

Less Able Pupils Understand that food passes along the alimentary canal.Appreciate that starch molecules are bigger than sugar molecules.Use Visking tubing as a model alimentary canal to investigate theabsorption of sugar, and recognise that sugar can pass through butstarch cannot.

More Able Pupils All the above, plus, appreciate that the alimentary canal is spatiallypart of the ‘outside world’, and that food molecules must cross itswalls before being of use to the body.Can bring together knowledge from several different sources topredict the results of an investigation.

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10 In and register. Pupils understand that swallowed food passes along theStarter. Introduce topic of digestion: What happens to food after it has been alimentary canal, and that this is a continuous tube. swallowed? Look at diagram on Pupil Book page 42 and discuss the idea that Understand that nutrients must cross the wall of the canal in the alimentary canal is really a part of the outside world. Introduce the concept order to get into the blood or cells, and that this process is of absorption. called absorption.

5 Development. Introduce Worksheet C4, Absorbing carbohydrates. Most pupils will remember how to test for starch Pupils bring together knowledge of particles, molecule size Ask pupils to tell you how they will test for starch and for sugar. and sugar, but less able pupils may need to be and food tests to predict the results of an investigation.Look at the diagrams on page 43 in the Pupil Book and point out the relative reminded about this.sizes of starch molecules and sugar molecules. Ask pupils to predict the results Most pupils should be able to predict that there they might expect from this investigation. will be sugar but no starch in the water. More able

pupils will be able to predict what this will mean in terms of the results of the tests in Worksheet C4.

25 Instruct groups to do the investigation on Worksheet C4. Support pupils as they Pupils have used Visking tubing as a model alimentary canal.work. They understand that sugar can pass through Visking tubing

but starch cannot.

10 Plenary. Discuss the results with the class. Talk through the answer to step 7 More able pupils may be able to suggest that on Worksheet C4. Relate this to absorption from the alimentary canal. Pose starch molecules could be broken down into sugar question – what could be done to starch to make it possible to absorb it from molecules so that they can be absorbed.the alimentary canal?Set homework.

Homework: Continue with your research and preparation of the presentation started in the homework for Lesson 4.


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Lesson Focus Pupil Book 2 p. 45Digestion is necessary before absorptionEnzymes as catalysts

ExpectationsMost Pupils Know that digestion is the breakdown of large molecules of food to

small ones, and that it is necessary before absorption can takeplace. Know that enzymes help in digestion and that amylasebreaks down starch molecules to sugar molecules.Investigate the digestion of starch by amylase.

Less Able Pupils Know that digestion is the breakdown of food and that it involvesenzymes. Know that amylase changes starch to sugar.

More Able Pupils All the above, plus understand that enzymes are catalysts and soare not changed in a reaction.




Worksheet C5 Digesting starchPer group:Reagents: Access to amylase solution,approx. 0.1% (see Teaching Notes page90 for more information onconcentration); access to starchsuspension, approx. 1%; iodine in KIsolution with dropper; Benedict's solutionwith dropperThree clean boiling tubes in a rack At least one clean glass rod (three ifavailable)Three syringes or small measuringcylinders to measure 10 cm3

A beaker and access to tap waterMeans of labelling the tubes Sight of clockA white tile (e.g. spotting tile)Access to a water bath of very hot water,with racks to hold boiling tubes

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5 In and register. More able pupils are likely to remember the Pupils reinforce the concept that food molecules must be Starter. Remind the class of the Visking tubing activity last lesson – reinforce results from last lesson, and to be able to relate absorbed through the wall of the alimentary canal, and that the idea that starch molecules were too big to get through the tubing, while this to absorption. only small molecules such as sugar can do this.sugar molecules were sufficiently small. Relate this to absorption from the alimentary canal.

10 Development. Discuss the concept of digestion, and introduce the terms Pupils understand the terms catalyst and enzyme. catalyst and enzyme (Pupil Book page 45). They recognise that digestion is a type of chemical reaction. Introduce and talk through Worksheet C5 Digesting starch. Safety: Instruct pupils to take great care while handling the hot water bath.

25 Instruct groups to do the investigation of Worksheet C5. Support pupils as Pupils use amylase to digest starch. They reinforce their they work. understanding of the use of controls in an investigation.

They reinforce their knowledge of the tests for starch and sugar.

5 Direct pupils to clear away apparatus, tidy the benches and then to settle.

5 Plenary. Discuss the conclusion drawn in answer to step 4 on Worksheet C5. Pupils know that amylase breaks down starch to sugar. Set homework.

Homework: Read the Literacy activity ‘Why rabbits can eat grass’ on page 47 of the Pupil Book, and answer the questions.


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Lesson Focus Pupil Book 2 pp. 45–46Investigating the effect of temperature on enzyme activityOne or two groups give presentation on an aspect of diet

ExpectationsMost Pupils Successfully carry out an investigation into the effect of temperature

on the activity of amylase. Use results of the investigation toconclude that amylase acts most effectively at ‘normal’ temperatures.Understand that enzyme activity is also affected by pH.

Less Able Pupils Investigate the effects of temperature on the activity of amylase, withsome success. Know that the effect of amylase is affected bytemperature and pH.

More Able Pupils All the above, plus relate findings from the investigation to theactivity of amylase and other enzymes in the alimentary canal.




Worksheet C6 How does temperatureaffect starch digestion?Per group:Six clean boiling tubes in a rackMeans of labelling the tubesA beaker and access to crushed iceAccess to a water bath containing veryhot water, containing racks to holdboiling tubesA thermometer White tileReagents: Access to 0.1% amylasesolution (or appropriate conc. aspreviously determined), and to 1% starchsuspension; iodine in KI solutionTwo syringes to measure 10 cm3

Three clean glass rods

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5 In and register. Starter. Introduce Worksheet C6 How does temperature affect starch digestion? Deal with any queries and emphasise the need to be organised.

25 Development. Instruct groups to carry out the investigation on Worksheet C6. Less able pupils will need more help in getting Pupils carry out an investigation which requires organising and Support pupils as they work. organised and in designing a results chart. completing several activities in a limited time.Allow any pupils who do not obtain a set of results to use those from another group.

10 Plenary. Discuss group findings. Help pupils to draw a conclusion (step 4 More able pupils will use their results to conclude Pupils know that the digestion of starch by amylase happens on Worksheet C6). Relate findings to the temperature inside the alimentary canal. that amylase breaks down starch most rapidly at most quickly at moderate temperatures, and less quickly at Tell pupils that seeds contain starch which is digested by amylase when the seeds room temperature. Less able pupils will need more very low or high temperatures.germinate: Would they expect this amylase to work best at human body help in interpreting results. Pupils make the generalisation that enzyme activity is affected temperature? by temperature, and they understand that not all enzymes Introduce the idea that enzyme activity is also affected by pH, and relate this to work best at human body temperature.enzymes in the alimentary canal. They know that enzyme activity is affected by pH.

10 Extension. Invite one or two groups to give presentations on the topic they have More able pupils are likely to lead the group Presenters gain experience in making a presentation; the rest researched for Lessons 4 and 5 homeworks. presentation, and to support less able pupils with of the class learn about a topic related to diet.

their contributions.

Homework: Answer End of chapter questions 1 and 3 on pages 49 and 50 in the Pupil Book. Revise for End of Unit test.


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Lesson Focus Pupil Book 2 Chapter 3End of Unit testGiving presentations on an aspect of diet

Expectations

Most Pupils Demonstrate secure knowledge and understanding of food anddigestion.

Less Able Pupils Demonstrate some knowledge and understanding of food anddigestion.

More Able Pupils All the above, plus interpret data on the results of an investigationand outline a good plan for a related investigation.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Calculating masses of nutrients in a mealICT:




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30 In and register. More able pupils will answer more questions Pupils consolidate knowledge gained by completing theDistribute the End of Unit test and instruct pupils to complete it. correctly and will attempt the extension question. End of Unit test.

20 Extension. Invite two or three groups to give presentations on the topics they More able pupils are likely to lead the group Presenters gain experience in making a presentation; the rest have researched. presentation, and provide support to less able of the class learns about a topic related to diet.

pupils with their contributions.

Homework: Do question 4 on page 50 in the Pupil Book.


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Minerals VitaminsFood Energy Protein Fat Carbohydrate Iron Calcium Vit A Vit B Vit C Fibre

(kJ) (g) (g) (g) (mg) (mg) (mg) (mg) (mg) (g)apples 150 0.2 0 9.0 0.2 0 0 0.1 2 2bananas 330 1.0 0.3 20.9 0.4 0 200 0.6 10 3baked beans 270 5.0 0.5 10.0 1.4 45 0 0.6 0 10beef 920 19.0 16.0 0 2.7 0 0 4.5 0 0biscuits 1850 9.5 16.0 68.0 1.7 100 0 1.6 0 6bread, brown 920 9.0 2.2 45.0 2.5 100 0 3.3 0 7bread, white 960 7.8 1.7 50.0 1.7 100 0 1.6 0 4broccoli 80 3.0 0 1.6 1.0 80 500 0.7 35 4butter 3140 0.5 82.0 0 0.2 15 1000 0 0 0cake 1380 4.0 11.0 58.0 1.8 75 1200 0.7 0 2carrots 80 0.6 0 4.0 0.4 40 12000 0.4 4 3chapatis 1420 8.0 13.0 50.0 2.3 70 0 1.8 0 7cheddar cheese 1670 26.0 34.0 0 0.4 800 400 0.5 0 0cottage cheese 420 14.0 0.5 1.5 0.1 60 30 0.2 0 0chicken 500 21.0 4.0 0 0.7 0 0.1 8.2 0 0chocolate 2220 8.0 30.0 59.0 1.6 220 0 0.2 0 0cola-type drinks 86 0 0 4 0 0 0 0 0crisps 2200 6.0 35.0 50.0 2.0 40 0 5.3 15 12custard 500 4.0 4.0 17.0 0 140 40 0.2 0 0egg, scrambled 1050 10.0 23.0 0 2.0 60 150 0.3 0 0fish fingers 960 13.5 13.0 17.0 0.7 45 0 1.5 0 0fruit juice 170 0 0 10.0 0.3 0 0 0.2 25 0ham 500 18.0 5.0 0 1.2 0 0 4.5 0 0hamburger 1090 20.0 17.0 7.0 3.1 35 0 4.0 0 0

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Note: The B vitamins are treated as one vitamin, for simplicity.

The nutrient content of 100 g of some foods

Minerals VitaminsFood Energy Protein Fat Carbohydrate Iron Calcium Vit A Vit B Vit C Fibre

(kJ) (g) (g) (g) (mg) (mg) (mg) (mg) (mg) (g)ice cream 710 4.0 7.0 25.0 0.2 140 0 0 0 0jelly 1090 6.0 - 63.0 2.0 30 0 0 0 0lentils 420 8.0 0.5 17.0 2.4 0 0 0.4 0 4lettuce 40 1.0 0 1.0 0.9 25 200 0.4 15 1.5margarine 3060 0 81.0 0 0 0 1000 0 0 0milk 270 3.3 3.8 4.7 0 120 50 0.1 1 0onions 100 1.0 0 5.0 0.3 30 0 0.05 10 1oranges 150 1.0 0 9.0 0.3 40 50 0.3 50 2pastry 2220 7.0 32.0 56.0 2.0 100 150 1.5 0 2.5peanuts 2390 24.0 50.0 9.0 2.0 60 0 17.0 0 6peas 210 5.0 0.4 8.0 1.2 0 50 2.8 25 5potatoes, baked 360 2.0 0 20.0 0.6 0 0 1.1 10 2potatoes, chips 1050 4.0 11.0 37.0 0.9 0 0 1.2 10 1raisins 1050 1.0 0 65.0 1.5 60 0 0.7 0 7rice, boiled 500 2.0 0.3 30.0 0 0 0 0 0 2sausages 1340 14.0 25.0 11.0 1.5 60 0 4.6 0 1soup 250 1.0 3.0 6.0 0.5 0 60 0 0 0spaghetti 500 4.0 0.3 26.0 0.4 0 0 0 0 0sugar 1630 0 0 100 0 0 0 0 0 0sweet potato 360 1.0 0.6 20.0 0.6 0 700 0.7 15 2tomatoes 60 1.0 0 3.0 0.4 0 15 0.8 20 1.5tuna, in oil 790 27.1 9.0 0 1.6 12 0 16 0 0yam 500 1.5 0 30.0 0.3 0 0 0.5 2 4yoghurt, fruit 330 5.0 1.0 14.0 0 170 0 0.3 0 0

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Note: The B vitamins are treated as one vitamin, for simplicity.

The nutrient content of 100 g of some foods

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Choose and collect samples of five different foods that you want to test.Arrange small quantities of them on a tile, not touching each other, as in thediagram.

Testing for protein

1 Chop up or crush a small sample of the first food, and put it into a testtube.

2 Add about 3 cm depth of biuret solution. Shake the tube, or stir with aclean glass rod, to mix the food and the biuret solution.

3 Record your result and conclusion (whether the food contains protein or not) in a table like this.

Results table for protein

Testing for fat

1 Read what you are going to do, and then draw a results chart similar tothe one you used for the results and conclusions of the protein test.

2 Chop or crush a sample of the first food, and put it into a very clean, drytest tube.

3 Add enough ethanol to cover the food. Shake the tube, or stir with a cleanglass rod, to mix the food and the ethanol.

4 Put some water into another clean test tube. Carefully pour some of theethanol in the tube with the food (do not pour in the food!) into thewater. If the water stays clear, then there is no fat in the food. If the watergoes milky white, it means that fat is present in the food.

5 For each food, record your result and conclusion in the table.

C1 Testing foods for protein

and fat

CHAPTER

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Food being tested Colour after adding Conclusionbiuret solution

If it stays blue, there is noprotein. If it turns purple, that

means protein is present.

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C2 Testing foods for

starch and sugar

CHAPTER

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Starch and sugar are two different kinds of carbohydrate.

Collect samples of five different foods that you want to test. Arrange smallquantities of them on a tile, not touching each other.

Testing for starch

1 Put a small sample of the first food onto a white tile. Add a few drops ofiodine solution.

2 Record your result and conclusion (whether thefood contains starch or not) in a table like this.

Results table for starch

Testing for sugar

1 Read what you are going to do, and then draw a results chart similar tothe one for starch.

2 Put a small sample of the first food into a boiling tube. Add about 3 cmdepth of Benedict's solution, and mix it with the food.

3 Stand the tube in a very hot water bath, and leave it for about 5 minutes.(You can be getting on with the other four foods while you are waiting.)

If there is sugar in the food, the colour will change from blue through asort of dirty green, then yellow, then orangey-red.

For each food, record your result and conclusion in the table.


Food being tested Colour after adding Conclusioniodine solution

If it stays orangey-brown, there isno starch. If it turns very dark

blue, that means starch is present.

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You will need labels from lots of different kinds of food in packages or tins.

1 Sort your labels into three groups:

• food from animals (for example, meat, fish, eggs, milk, butter)

• food from plants (for example fruit, vegetables, baked beans)

• food from both animals and plants, or where you are not sure where it comes from.

2 Choose a colour for each of the three groups and add the colours to theKey in the Nutrients in foods chart. List each food across the first row ofthe chart. Lightly shade all the way down each column using theappropriate colour for that food.

3 Using the information on the labels, fill in the chart as fully as you can toshow how much of each nutrient is present in 100 g of the food.

4 Look for patterns in the kinds and quantities of nutrients in the differentkinds of food. Describe any differences you can see between the foodsthat come from animals, and the foods that come from plants. Forexample:

• Which of them contains the most protein?

• Which are the best source of vitamin C?

• Which contain the most saturated fats?

C3 Which foods are good

sources of nutrients? (page 1)

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➤continued

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Food:

Energy in kJ

Protein in g

Carbohydrate in g,

of which sugar

Fat in g,

of which saturates

Fibre in g

Sodium in g

Iron

Calcium

Vitamin A (retinol)

Vitamin B1 (thiamine)

Vitamin B2 (riboflavin)

Vitamin C (ascorbic acid)

Vitamin D (niacin)

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Chart C3: Nutrients in foods

Colour key for foods

From animals

From plants

From animals and plants (or not sure)

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C4 Absorbing

carbohydrates

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You are going to use a piece of Visking tubing to represent thealimentary canal. The tubing has tiny, molecule-sized holes in it. (Theyare much, much too small to see.) The holes are big enough to letsmall molecules through, but too small to let large molecules through.

1 Collect a piece of Visking tubing. Moisten it with water, then rub itbetween your fingers until it opens into a tube. Tie a knot in it atone end, as shown on the right.

2 Using a dropper pipette, ‘feed’ your piece of tubing with a ‘meal’ ofstarch and sugar mixed with water.

3 Tie some cotton very tightly around the top of the tubing to make aclosed bag. (Two pairs of hands are much better than one for this.)Rinse the tubing with water, to remove any of the 'meal' that mayhave spilled onto the outside of it.

4 Put the tubing into a beaker or other container. Add enough waterjust to cover the tubing, like this:

5 After about 10 minutes, take a small sample of the water from the beakerand test it for starch. Record your result in your workbook.

6 Take another sample of the water from the beaker, and test it for sugar.Record your result.

7 Copy and complete the sentences below, using these words:

diffusion sugar starch water

The meal inside the Visking tubing contained molecules of ....................,........................ and ....................... . At the start of the experiment, the waterin the beaker contained only molecules of water.

During the experiment, some of the molecules went back and forth throughthe holes in the Visking tubing, by ....................... . Only the small moleculescould do this. These were the ..................... molecules and the ........................molecules. So, by the end of the experiment, the water in the beakercontained ..................... molecules as well as water molecules. The ..................molecules were too big to get through the holes in the tubing, so theystayed where they were.

Visking tubing

starch, sugarand water

water

119

Amylase is an enzyme that is found in saliva. You are going to find out whateffect amylase has on starch molecules.

1 Set up three boiling tubes like this:

Use a clean glass rod to stir the contents of each tube so that they arethoroughly mixed.

2 After about 10 minutes, test the contents of each tube to find out if anystarch is present, like this:

Draw a results chart and record your observations and your conclusions in it.

C5 Digesting starch (page 1)

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10 cm3 starch solution

+

10 cm3 water

10 cm3 starch solution

+

10 cm3 amylase

10 cm3 water +

10 cm3 amylase

A B C

Add your sample to a drop of iodine solution on a white tile

Use a dropperpipette to collecta small samplefrom the tube

➤continued

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C5 Digesting starch (page 2)

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3 Now test the contents of each tube to find out if any sugar is present, likethis:

Record your observations and your conclusions in your results chart.

4 Write a conclusion to your investigation. Try to do this in no more thantwo sentences, saying what you have found out about the effect thatamylase has on starch.

Then describe how the evidence you saw helped you to come to thisconclusion.


121

Inside the alimentary canal, the temperature is always about 37°C. Woulddigestion happen any faster or any slower if the temperature was differentfrom this?

In this investigation, you are going to try to answer the question:

Does temperature affect the rate at which amylase works?

Once you get to stages 2 and 3, everything happens very quickly. It's a goodidea to make sure you are thoroughly organised before this. Use the timewhile you are waiting in step 1 to draw a results chart, ready to fill in duringstep 3.

1 Set up six boiling tubes, like this:

Measure and record the temperature in the crushed ice, in the room andin the water bath.

2 After 10 minutes, tip the amylase solution into the starch solution next toit. Using a clean glass rod for each one, stir them to mix up the amylasewith the starch.

3 Every 2 minutes (more often if you can manage it!), take a small sample ofthe liquid from each tube and test it to see if it still contains starch. Keep avery careful record of your results.

4 Write a short conclusion, answering the question at the start of thisinvestigation. Then explain how your results helped you to answer thisquestion.

C6 How does temperature

affect starch digestion?

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We use our teeth to chew food. This breaks it up into smaller pieces.

Plan an investigation to answer the question:

Does chewing help amylase to break down the starch in bread faster?

You don't need to actually chew the bread – you can just break it up intosmall pieces.

C7 How do teeth help with

digestion?

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1 Which variable will you change?

2 Which variable will you keep the same, to make it a fair test?

3 Which variable will you measure? How will you measure it?

4 What materials and apparatus will you need?

5 What do you think will happen?

6 Why do you think this will happen?

7 How will you carry out the experiment?

8 What safety measures do you need to take?

9 How will you record your results?


1 This table shows some of the nutrients that are contained in 100 g of sevendifferent foods and two kinds of drinks.

a Which food in the table is the best source of protein?

..............................................

(1)

b Chris is a vegetarian. Which four foods in the table would be the best sources of protein for him?

..............................................................................................................

(2)

c Andrew is worried about his weight and his heart, and wants to avoid eating too much fat in his diet. Which two foods in the table should he avoid eating?

............................... and .................................

(1)

d Suggest why it is a good idea to eat brown bread rather than white bread.

...........................................................................................................

...........................................................................................................

(2)

e Lena eats a hamburger containing 200 g of fried minced meat inside a 100 g white bread roll. Calculate how much protein there is in her meal. Show your working.

...................................................................................................................... g

(2)

End of Unit test

Food and digestion

CHAPTER

3

Food Protein (g) Fat (g) Carbohydrate (g) Fibre (g)fried minced meat 20.0 17.0 7.0 0white bread 7.8 1.7 50.0 4.0brown bread 9.0 2.2 45.0 7.0chips 4.0 11.0 37.0 2.0roast chicken 25.0 5.0 0 0baked beans 5.0 0.2 10.0 4.0fresh tomatoes 1.0 0 3.0 1.5can of fizzy drink 0 0 6.0 0milk 3.3 3.8 4.7 0

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f Name two groups of nutrients that are not shown in the table.

................................... and .............................

(2)

g Which nutrients shown in the table provide us with energy?

................................................................................................

(1)

2 This table is about how to test for the different types of nutrients in food.Fill in the empty boxes.

(5)

3 The diagram shows a starch molecule.

a The starch molecule is made of lots of small molecules linked together. What are these small molecules?

...........................................

(1)

b What is the meaning of the term digestion?

...................................................................................................

(1)

c Explain why starch needs to be digested in our alimentary canal.

.............................................................................................................

(1)


Nutrient What you do What you see if thenutrient is present

starch very dark blue colour

add Benedict's solution the mixture becomes aand heat strongly reddish-orange colour

protein

fat add ethanol and mix,then pour some of theethanol into water



d Amylase is an enzyme that helps to digest starch.Name one part of the alimentary canal where amylase is made.

.......................................................

(1)

e Complete these word equations, to show how proteins and fats are digested in the alimentary canal. (You need to write in the name of the enzyme in each equation, and also the products of the reactions.)

.........................proteins ...........................

.........................fats ........................... + ......................

(5)

Total marks: 25

Extension question

4 Caroline investigated how temperature affected the activity of a proteaseenzyme. She mixed up some milk powder and water, to make a milky liquid.She found that if she added protease, it broke down the protein in themilky liquid and the liquid went clear.

Caroline set up five tubes of milky liquid and kept them at five differenttemperatures. Then she added protease to each tube, and timed how long ittook for the liquid to go clear. These were her results.

a Suggest three things that Caroline should have kept the same in all five tubes.

..........................................................................................................

..........................................................................................................

.........................................................................................................

(3)

b At which temperature did the protease enzyme work most quickly?

...........................................................................................................

(1)

Temperature (°C) 0 20 40 60 80

Time taken for liquid the liquid neverto go clear (seconds) 400 160 40 110 went clear



c Suggest why the liquid never went clear at 80 °C.

........................................................................................................

........................................................................................................

(2)

d Caroline's teacher suggested that Caroline could also investigate how the activity of the protease enzyme was affected by pH. Describe how she could do this.

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

........................................................................................................

.......................................................................................................

(4)




Text answers

1 a Protein, carbohydrate and fat b 2.1 gc 92.2 g d 7.8 ge It is water

2 a proteins b carbohydrates, energyc fats d fibree vitamins and minerals

3 a It contained starch. b It would go orange-red.c (i) protein (ii) She should not have heated it.

4 protein: milk, meat, fish, eggs, cheese, brown bread, beans, breakfast cerealfat: milk, meat, eggs, cheesecarbohydrate: milk, fresh fruit, brown bread, beans, breakfast cerealminerals and vitamins: all of these foodsfibre: fresh vegetables, fresh fruit, brown bread, beans, breakfast cereal

5 The cell membrane (because this is the part of the cell that controls whatgoes in and out).

6 proteaseprotein amino acids

lipasefats fatty acids + glycerol

7 The liver and the pancreas.

Literacy activity answers

a The cell walls.b A carbohydrate.c Cellulose is made of large molecules, which cannot be absorbed. We do not

have an enzyme that can digest cellulose, so we cannot break these largemolecules down.

d The bacteria have a warm place to live, with a constant supply of food.e The faeces produced during the day have been made from the re-eaten

food. There is no need to eat them again, as all the nutrients will alreadyhave been absorbed from them.


1 a sugar b amino acidsc hydrochloric d lipasee protein f waterg digestion h absorptioni carbohydrate j balanced

2 a Proteins, fats, carbohydrates, vitamins, minerals, water, fibreb Andrew needs less energy-containing food in his diet, because he does

not use up so much energy. He should eat less fat and carbohydrate than Jack.

3 a D b Cc E d Fe A or E f Dg E h E

Food and digestionCHAPTER

3

ANSWERS

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Worksheet answers

C4 Absorbing carbohydratesStep 7: water, sugar and starchdiffusion, water, sugar, sugar, starch


1 a Roast chicken (1)b Brown bread; white bread; baked beans; chips (1/2 mark each) (2)c Fried minced meat, chips (1)d It has more fibre; which keeps the alimentary canal healthy (2)e 40 g in the minced meat + 7.8 g in the bread = 47.8 g (2)f Vitamins; minerals (2)g Proteins, fats and carbohydrates (1)

2 Add iodine solutionSugarAdd biuret reagent; purple colourMilky/cloudy (total 5)

3 a Sugar/glucose (molecules) (1)b Breaking down large molecules into small ones (1)c Starch molecules are too big to be absorbed (1)d Salivary gland/mouth/pancreas (1)e Protease, amino acids;

lipase, fatty acids + glycerol (5)

Total marks: 25

Extension answers

4 a The volume of milky liquid; the volume of protease (solution); the concentration of milk powder in the liquid; the concentration of the protease (solution) (any three, 3)

b 40 °C (1)c The protein was not broken down; because the protease had been

destroyed (do not allow ‘killed’) (2)d Set up several tubes all at a different pH; at the same temperature (no

higher than 60 °C); put the same volume of milky liquid into each tube; add the same volume of protease solution to each tube; time how long it takes for the liquid to go clear (any four, 4)





Chapter 3 Answers

Pupils should be familiar with the following ideas:• The names of some elements• That there are about 100 elements• Elements are composed of atoms• Compounds are formed when atoms of different elements join• How to make and separate mixtures

4 Compounds and mixtures

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Starting points


AtomBoilingBoiling pointChemical reactionChromatographyCompound

CondenseCrystallisationDistillationElementFiltrationFormula

Fractionaldistillation

FreezingFreezing pointMeltingMelting point

MixtureMoleculeProportionPure

In this topic pupils should learn:• the names of some common elements, mixtures and compounds• how to recognise atoms in elements, mixtures and compounds in diagrams• how to represent some simple compounds using formulas and to appreciate the

information that the formula of a compound gives about the number and typeof atoms that are present

• about a range of separation techniques, and suggest how certain mixtures maybe separated

• that elements and compounds melt at fixed temperatures called melting points• that elements and compounds boil at fixed temperatures called boiling points• that mixtures melt and boil over a range of temperatures• how to explain melting and boiling using the particle model

Learning checklist

Links

7.5HRS

TE

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Unit Title7G Particle Model of Solids, Liquids and Gases7H Solutions8E Atoms and Elements8I Heating and Cooling


CH A P T E R

4

T I M I N G

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Cross-curricular links

LiteracyThere is a literacy activity within the Pupil Book on Joseph Priestley.

NumeracyTemperature lines use negative numbers.

ICTSpreadsheets can be used to record data.Making a leaflet on air provides an opportunity to use ICT.Optional use of internet to find melting and boiling points.


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ICT

Most pupils

Scientific enquiry• Make observations and measurements of mass and temperature• Present results as line graphs and interpret theseMaterials and their properties• Distinguish between elements, compounds and mixtures• Name and describe some common mixtures• Suggest how mixtures might be separated• Identify melting and boiling points as the temperatures at which elements and

compounds change state• Use the particle model to explain changes of state


Scientific enquiry• Make observations and measurements of mass and temperature• Present measurements as line graphs, with helpMaterials and their properties• Name some common elements, compounds and mixtures• Distinguish between models of these• Describe how mixtures might be separated• Recognise changes of state in elements and compounds


Scientific enquiry• Explain why the scales they chose for graphs meant the results were presented

effectively• Make suggestions of additional work to test conclusions of their investigationsMaterials and their properties• Explain their criteria for classifying materials as elements, compounds or mixtures• Represent some compounds by formulas• Explain what the formulas show about the numbers and types of atom present• Describe how mixtures do not change state at fixed temperatures

Learning outcomes


132


Elements and compoundsThis topic builds upon the work covered in Chapter 1, Atoms and elements. Thefirst activity in the Pupil Book is designed simply to remind pupils of the workthey covered in Chapter 1. Pupils should recall that elements are made of justone type of atom, while compounds contain two (or more) different types ofatom that have been joined together. If preferred, the same activity could becompleted by using the statements as individual cards using Worksheet D1,Elements and compounds.

Elements, mixtures and compoundsIn this section pupils should explore the properties of mixtures and compounds.Pupils should be given small samples of the elements sulfur and iron. Pupilsshould be asked to make a mixture from the two elements. Pupils should behelped to appreciate that although the two elements have been mixed together,each element still retains its own properties (elements are the same colour, iron isstill magnetic). Pupils should then watch a 7:4 by mass iron to sulfur mixturebeing heated. The heating could be done as a demonstration or very carefully bypupils. When the compound has cooled, its properties can be compared with theproperties of the two elements. Pupils should appreciate that they have made anew material and that a compound can have very different properties from theelements from which it is made. Pupils can be helped to write a word equation todescribe the reaction.

Safety – eye protection should be worn throughout.

Models of elements, compounds and mixturesPupils should also be shown diagrams to represent the atoms in elements,mixtures and compounds. As a homework activity pupils could do WorksheetD2, Particle models.

How can we tell if a compound reacts?Pupils should be reminded of the work covered in Year 7 Pupil Book 1 Chapter 6,Simple chemical reactions, on the ways that a chemical reaction can be observed.They should be made aware that they should look for bubbles (which show that agas is being produced), a change in colour, a new smell or a temperature change.The Pupil Book could be used as a source for discussion.

Pupils should then be given the opportunity to carry out a series of simplereactions using Worksheet D3, Observing reactions. For each experiment theyshould record their observations, and in small groups decide upon the evidencethat they have found to confirm that a chemical reaction has taken place. Pupilscan then be helped to summarise their results using the Pupil Book. It should bestressed to pupils that in all chemical reactions there is a change in the way inwhich the atoms are joined together.

Safety – eye protection should be worn throughout.

MixturesPupils should be reminded of the work on mixtures covered in Year 7 Chapter 9,Solutions. Pupils should be asked to name some mixtures and to explain what ismeant by the term ‘mixture’ and why a mixture is different from a compound.(Mixtures can vary in composition, while compounds have a fixed compositionand can be represented using a formula.) The Pupil Book can be used as a sourceof material for discussion.

!

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Mineral waters... mixtures or compounds?Pupils should look at the labels from two different mineral waters shown in thePupil Book, and appreciate that mineral waters are mixtures whose compositionscan vary. Pupils can then be asked about the term ‘pure’. In science ‘pure’ has aspecific meaning (only one substance) and the term can be applied to bothelements and compounds. Pupils should also be shown the diagrams in the PupilBook representing (pure) elements, (pure) compounds and mixtures.

Separating mixturesPupils should be reminded of the separation techniques that they studied in Year7: filtration, crystallisation, distillation and chromatography.

Separating the gases in airIn this section pupils should find out about how air can be separated into itsconstituent gases, about the relative proportions of gases in air and about someof the uses of these gases. Pupils should then produce a leaflet about air.

Melting and boilingIn this section pupils will investigate how melting and boiling points can be usedto identify pure elements and compounds and to differentiate between puresubstances and mixtures. Pupils should be shown the temperature line on page59 of the Pupil Book, and helped to mark on this line the melting and boilingpoints of a number of different elements.

Pupils are then asked to mark on the temperature line the melting and boilingpoints of some compounds. Pupils should note that both elements andcompounds have fixed melting and boiling points, and that these can be used toidentify what the element or compound is.

Melting and freezingPupils should then be asked to find the melting and boiling points of somemixtures; for example, butter or air. They should realise that mixtures do nothave fixed melting and boiling points, and that they actually change state over arange of temperatures.

How does salt affect the boiling point of water?Pupils can then investigate the boiling points of pure and salty water usingWorksheet D4, Boiling points of pure and salty water. They should find that purewater is a compound and boils at the expected temperature of 100 °C, but if salt is added to the water (to form a mixture) that the boilingpoint will change.

How does adding salt affect the freezing point of water?In this section pupils should investigate how the temperatures of a pure liquidand an impure liquid change as they cool. Worksheet D5, Investigating a pureand an impure liquid, could be used to introduce this activity. Pupils should betold that they will be given two liquids which will be labelled ‘a’ and ‘b’. Theyshould be told that one of the two liquids is (pure) distilled water, which is acompound, while the other is (impure) salty water, which is a mixture. Pupilsshould be shown how to use an ice/salt mixture and should consider what resultsthey should record and how often these results should be taken. Pupils should behelped to plot a graph of temperature change against time, and asked to decidewhich of the two mixtures is distilled water and which is salty water. Pupilsshould be asked to explain how they have come to their conclusions. Thedifference in freezing points between distilled water and salty water is discussedin the Pupil Book.



Safety –pupils’plans mustbe checkedfor healthand safetybeforepracticalwork starts.

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Elements and compoundsA selection of molecules and ionic compounds has been included and thisdistinction can be discussed with more able pupils.

Elements, mixtures and compoundsWrap the magnets in clingfilm before this experiment so that the iron can beeasily removed at the end.

If pupils are allowed to heat the iron and sulfur mixture it should be done verycarefully and pupils should be warned that if the sulfur is heated too fiercely itmay begin to burn and produce the toxic gas sulfur dioxide.

Some pupils may benefit from being shown the atom model bricks used inChapter 1, Atoms and elements.

How can we tell if a compound reacts?Some pupils will benefit from seeing Megan’s experiment on page 54 of the PupilBook set up as a real demonstration.

If time is limited then some of the reaction could be allocated to each group andresults shared at the end.

MixturesIf time and resources allow, pupils may benefit from being able to see real bottlesof mineral water with real labels. Many pupils will be quite confused over theterm ‘pure’ and try to equate it with the term ‘natural’.

Some pupils may benefit from practising the skills involved in separating mixtureswith the different separation techniques discussed in this section.

Melting and boilingMore able pupils may supplement the elements and compounds given in thePupil Book with others found using secondary sources (data books, internet).

Melting and freezingPupils may not appreciate that since freezing and melting are opposites, they willoccur at the same temperature.

How does adding salt affect the freezing point of water?Less able pupils may find it very difficult to plot the temperature against timegraph on Worksheet D5 successfully and might benefit from a set of suitableaxes being made available for them to see.



Sc1

Scientific Enquiry

1a, 1c, 2b, 2e

Sc2


Sc3


1a, 1c, 1d, 1e, 1f,1g, 1h

Sc4

Physical Processes



What I have learnt

Compounds and mixtures


Molecule

Boiling

Proportion

Filtration

Chemical reaction

Compound

Boiling point

Atom

Element

Pure

Freezing

Formula

Melting point

Chromatography

MixtureCondense

Distillation

Crystallisation

Fractionaldistillation

Freezing point

Melting


• I know the names of some elements,mixtures and compounds

• I can distinguish between diagramsshowing atoms in elements, mixturesand compounds

• I can use formulas to represent somecompounds

• I know how mixtures can beseparated

• I know what the melting point of anelement is

• I know what the boiling point of anelement is

• I know that mixtures melt and boilover a range of temperatures

• I can use the particle model toexplain melting and boiling

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on this topic

CHECKLIST

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Lesson Focus Pupil Book 2 pp. 51–54Elements, compounds and mixtures

ExpectationsMost Pupils Know that when two elements are mixed together then the

elements retain their properties, but that when two elements arejoined together during a chemical reaction to form a newcompound, then this new compound can have very differentproperties.

Less Able Pupils Can distinguish between the formulas for elements and forcompounds.

More Able Pupils All the above, plus can use diagrams to represent the arrangementof atoms in elements, mixtures and compounds with confidence.



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Worksheet D1 Elements andcompoundsOne per pupil plus access to scissors

Pupil investigation: properties of amixturePer group:A mixture of iron and sulfurA magnet (wrapped in clingfilm)Hydrochloric acid

Demo: Making a new compoundIron and sulfur in a 7:4 ratio to heatcarefully

Worksheet D2 Particle modelsFor homework

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15 In and register. The distinction between simple molecular Pupils are reminded of definitions of elements and Starter. Use Q and A to remind pupils of their previous work about elements compounds and ionic compounds can be compounds and can practise interpreting chemical formulas.and compounds (Chapter 1, Atoms and elements). discussed with more able pupils.Distribute Worksheet D1 Elements and compounds. Instruct pupils to carry out the activity.

15 Development. Pupil investigation: properties of a mixture. Distribute a Less confident pupils may need more help to Pupils should realise that in a mixture the constituent parts mixture of iron and sulfur, a magnet and some acid to each group. Instruct carry out the practical. retain their individual properties.pupils to investigate the properties of this mixture.

10 Demo: making a new compound. Show pupils a mixture of iron and sulfur Less able pupils will need more help to write the Pupils know that when a chemical reaction takes place that being heated. Explain that they are watching a chemical reaction and that a word equation. new substances are made and that these new substances can new compound has been formed. have very different properties.Help pupils to write a word equation for the reaction as the compound cools and then test the properties of the new compound.

10 Plenary. Instruct pupils to complete question 3 on page 53 of the Pupil Book. Less able pupils will need more help to relate to Pupils can relate diagrams to the arrangement of atoms in Then explain how diagrams can be used to represent the arrangement of atoms diagrams and may benefit from using the atom elements, mixtures and compounds.in elements, mixtures and compounds. model bricks from Chapter 1.

Homework: Worksheet D2 Particle models.


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Lesson Focus Pupil Book 2 pp. 54–55Can compounds react?

Expectations

Most Pupils Use discussion to decide whether a chemical reaction has takenplace.

Less Able Pupils Know what to look for to show that a chemical reaction is takingplace.

More Able Pupils Can decide whether a chemical reaction has taken place.



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Worksheet D3 Observing reactionsFor each group:Heating sucrose: boiling tube, Bunsenburner, sugarAn acid with a metal carbonate:hydrochloric acid, calcium carbonate,boiling tube, thermometerSodium carbonate solution withiron(II) chloride: test tube, sodiumcarbonate solution, iron(II) chloridesolutionDilute ammonia and copper sulfatesolution: test tube, dilute ammonia,copper sulfate solution

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10 In and register. More able pupils will take a more active part in Pupils are reminded that they should look for bubbles, a Starter. Use Pupil Book to remind pupils of how they can tell that a chemical a group discussion. change in colour, a new smell or a temperature changereaction is taking place (Year 7 Pupil Book 1 Chapter 6, Simple chemical reactions).

30 Development. Distribute Worksheet D3 Observing reactions. Introduce the Less able pupils will require more help to carry Pupils carry out a series of small experiments safely and use activities and instruct pupils to carry out the instructions on the worksheet. out the experiments and record their results. discussion to decide whether a chemical reaction has taken For each experiment pupils should record their observations and then decide place.whether a chemical reaction has taken place.

10 Plenary. Pupils should use the Pupil Book to summarise their results. Help Pupils can consolidate their understanding.pupils to appreciate that in all chemical reactions there is a change in the way in which the atoms are joined together.

Homework: Complete summarising the reactions using the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 56–58Mixtures

Expectations

Most Pupils Can explain what is meant by the term ‘pure’.

Less Able Pupils Can explain what is meant by the term ‘mixture’ and give someexamples of mixtures.

More Able Pupils All the above, plus can explain how air can be separated and givesome uses of these gases.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Consideration of the boiling points of gases.ICT:


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OptionalBottles of different types of mineral wateror labels from them

Leaflet about airPlain paper, coloured pencils

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10 In and register. More able pupils take a more active part in Pupils know that mixtures vary in composition while Starter. Remind pupils of the previous work on mixtures. Use Q and A to discussion. compounds have a fixed composition.explore the differences between mixtures and compounds.

10 Development. Use page 56 of the Pupil Book on mineral waters and labels from Less able pupils will need more help to relate to Pupils know that pure means only one substance.mineral water bottles as source material to discuss the term ‘pure’. Explain the diagrams.that pure means only one substance and that the term can be applied to bothelements and compounds.

10 Remind pupils of the separation techniques that they have studied previously Less able pupils may benefit from demonstrations Pupils are reminded of a range of separation techniques and and instruct pupils to complete question 7 on page 58 of the Pupil Book of some of these techniques. why a particular technique is used in different situations.

20 Plenary. Use the Pupil Book to explain how air is separated. Then instruct pupils Pupils gain a basic understanding of how air can be separated to make a leaflet to show what they have learnt about air. into its constituent gases.

Homework: Complete leaflet about air.


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Lesson Focus Pupil Book 2 pp. 59–61Using melting and boiling points

Expectations

Most Pupils Can use a temperature line with confidence.

Less Able Pupils Know that pure substances have fixed melting and boiling points.

More Able Pupils Know that mixtures do not have fixed melting and boiling points,but change state over a range of temperatures.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Temperature lines incorporating negative numbers.ICT: Optional use of internet to find the melting and boiling points of elements and compounds.


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Information sheet Temperature line

Worksheet D4 Boiling points of pureand salty waterPer group:Two beakersSaltThermometerBunsen burnerDistilled water

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15 In and register. More able pupils may supplement the elements Know that pure elements and pure compounds have fixed Starter. Use the Pupil Book to introduce the concept of temperature lines. and compounds given in the Pupil Book with melting and boiling points.Instruct pupils to draw a temperature line and to mark on the melting and others found using secondary sources such as data boiling points of the elements and compounds shown in the Pupil Book. books or the internet.

Less able pupils may not realise that freezing and melting are opposites which occur at the same temperature.

5 Development. Explain how the melting point of a pure element or compound Know how to identify an element/compound from its can be used to identify it. Instruct pupils to answer question 13 on page 60 of melting/boiling point.the Pupil Book.

5 As a source for class discussion ask pupils to mark on their temperature line the More able pupils will take a more active part in Pupils realise that mixtures do not have fixed melting and melting point of butter and air. class discussion. boiling points, but melt or boil over a range of temperatures.

15 Distribute the Information sheet: Temperature line and Worksheet D4 Pupils measure the boiling points of pure and salty water.Boiling points of pure and salty water. Introduce the activity and ask pupils to carry out the investigation.

10 Plenary. Discuss the pupils’ results and explain the difference in boiling points Pupils can consolidate their ideas.of pure and salty water.

Homework: Answer questions 11 and 12 on page 60 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 60–62Investigating a pure and an impure liquid

Expectations

Most Pupils Can carry out an investigation and plot a graph of temperatureagainst time. Use their graph to differentiate between distilledwater and salty water.

Less Able Pupils Can carry out an investigation to tell apart distilled water and saltywater.

More Able Pupils All the above, plus explain how they came to their conclusionsusing scientific theory.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Plotting a temperature–time graph to include negative numbers.ICT:


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Worksheet D5 Investigating a pureand an impure liquidPer group:SaltIce cubesBeakers/bowlsTimerThermometersTwo boiling tubesSolutions labelled ‘a’ and ‘b’ (salty waterand distilled water)Plain paper, graph paper

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10 In and register. More able pupils will take a more active part in Pupils are reminded that pure substances have fixed melting Starter. Use Q and A to remind pupils that pure substances have fixed melting a group discussion. and boiling points.and boiling points.

20 Development. Distribute Worksheet D5 Investigating a pure and an impure Less able pupils will need more help to record Pupils can plan and carry out an investigation safely.liquid. Introduce the activity and show the pupils how to use a salt/ice mixture. their results.Help pupils to plan and then carry out their investigation.

10 Help pupils to plot a graph of their results. Less able pupils may benefit from a template of Pupils plot a graph of their results.suitable axes being made available.

10 Plenary. Use class discussion to decide which of the solutions is pure, distilled Pupils can explain how they have come to their conclusions.water and which is impure, salty water. Ask pupils to explain their conclusions.

Homework: Read and make notes on the effect of impurities on freezing point, pp. 60–62 of the Pupil Book.


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Lesson Focus Pupil Book 2 Chapter 4Revision and consolidation of Chapter 4

Expectations

Most Pupils Will have an understanding of the differences between mixturesand compounds.

Less Able Pupils Will have a basic understanding of the topic.

More Able Pupils All the above, plus will be fluent in all aspects of the topic using afull range of subject specific vocabulary.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Identify and explain the key words. Literacy activity on Priestly.Numeracy:ICT:


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20 In and register. Pupils have a record of the main ideas of the topic.Remind pupils of the main ideas of the topic. Direct pupils to answer questions 1 and 2 on page 65 of the Pupil Book.

30 Sit pupils in appropriate test conditions. Pupils complete the End of Unit test. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the correctly and will attempt the extension question. End of Unit test.

Homework: Questions 3 to 6 on pages 65–66 of the Pupil Book.


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UN I T

D1 Elements and compoundsCHAPTER

WORKSHEET1

4Copy the headings and cut out the rectangles below them.

Name Formula Composition

MgO two atoms of chlorinejoined together

H2O two atoms of oxygenjoined together

S8 one atom of copper combined chemically withone atom of carbon andthree atoms of oxygen

Cl2 one atom of magnesium combined chemically withone atom of oxygen

O2 two atoms of hydrogen combined chemically withone atom of oxygen

CuCO3 eight atoms of sulfurjoined together

1 Match the name of each material to its formula andcomposition.

2 Which of the substances above are elements and which arecompounds?

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yellowsulfur

oxygen

chlorine

magnesiumoxide

magnesium oxide

copperrbonate

coppercarbonate

water


The boxes below show how the particles are arranged in the elementsmagnesium, oxygen and nitrogen and in the compound magnesium oxide.

1 In the box below draw how atoms could be arranged in the elementcopper.

2 In the box below draw how atoms could be arranged in a mixture ofoxygen and nitrogen.

3 In the box below draw how atoms could be arranged in the compoundcopper oxide.

UN I T

D2 Particle modelsCHAPTER

WORKSHEET2

4

magnesium magnesium oxideoxygen nitrogen


UN I T

D3 Observing reactions (page 1)

CHAPTER

WORKSHEET3

4

Carry out the five experiments below. For each of the experiments record yourobservations. Then explain how you know that a chemical reaction has takenplace. The first one has been done for you.

Reacting magnesium with an acidInstructionsPlace a 2 cm length of magnesium ribbon into a test tube of dilute acid.

ObservationsBubbles appear and the test tube gets slightly warmer.

EvidenceThe bubbles and temperature increase show that a chemical reaction is takingplace.

Heating sucroseInstructionsPlace two spatulas of sucrose into a boiling tube. Then gently warm using aBunsen burner.

Observations

.................................................................................................................................

.................................................................................................................................

Evidence

.................................................................................................................................

.................................................................................................................................

Reacting an acid with a metal carbonateInstructionsPlace a 2 cm depth of acid into a boiling tube.Then add a small marble chip (calcium carbonate).

Observations

.................................................................................................................................

.................................................................................................................................

Evidence

.................................................................................................................................

.................................................................................................................................

➤continued


UN I T

D3 Observing reactions (page 2)

CHAPTER

WORKSHEET3

4

Reacting sodium carbonate solution withiron chloride solutionInstructionsPlace a 2 cm depth of sodium carbonate solution into a test tube. Carefullyadd a further 2 cm depth of iron chloride solution.

Observations

.................................................................................................................................

.................................................................................................................................

Evidence

.................................................................................................................................

.................................................................................................................................

Reacting dilute ammonia with copper sulfatesolutionInstructionsPlace a 2 cm depth of copper sulfate solution into a test tube. Carefully add afurther 2 cm depth of dilute ammonia.

Observations

.................................................................................................................................

.................................................................................................................................

Evidence

.................................................................................................................................

.................................................................................................................................


UN I T

For answering question 9 on page 59 of the Pupil Book.

Information sheet

Temperature line

CHAPTER

4

+3150+3000

+2250

+1050

+2850+2700+2550+2400

+2100+1950+1800+1650+1500+1350+1200

+900+750+600+450+300+150

0–150–300

Tem

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)

Coldest

Hottest

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D4 Boiling points of

pure and salty water

CHAPTER

WORKSHEET4

4


1 Place 100 cm3 of distilled water into a beaker.2 Using a Bunsen burner heat the water as shown, until it begins to boil.

3 Record the temperature of the water as it boils.4 Place 100 cm3 of distilled water into a second beaker.5 Add two spatulas of salt to the water.6 Use the Bunsen burner to heat the salty water.7 Record the temperature of the salty water as it boils.

1 Compare the boiling points of pure water and of salty water.Which is higher?

2 Why does salty water boil at a slightly different temperaturefrom pure water?

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250 cm3

beaker

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tripod

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You have been given two liquids labelled ‘a’ and ‘b’. One of the liquids isdistilled water which is a compound. The other is salty water which is amixture.

In this investigation you should find out how the temperatures of the twoliquids change as they are cooled using an ice/salt mixture.

Think about how you will carry out the investigation. In three sentenceswrite down your plan.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Decide on the readings that you will need to take in your investigation.Complete the headings in the table to show the readings that you will take.

Now carry out your investigation and record your results in your table.

D5 Investigating a pure

and an impure liquid (page 1)

CHAPTER

WORKSHEET5

4

Time (mins)

0

1

a b

➤continued

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D5 Investigating a pure

and an impure liquid (page 2)

CHAPTER

WORKSHEET5

4

1 Which of the liquids ‘a’ or ‘b’ is distilled water and which issalty water?

2 How did you identify the liquids?3 Describe two other ways you could use to identify the liquids.

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Draw a graph similar to the one shown below. Mark on the graph two linesto show how the temperatures of the two liquids ‘a’ and ‘b’ change as theliquids cool.


1 Use the words below to complete the passage.

mixturecompoundatom

Elements are made of only one type of ............................ . If the atoms of

two or more elements are joined together a ............................ is formed.

If the atoms of two or more elements are mixed together, but are not joined

a ............................ is formed.

(3)2 Tom has added some zinc to a flask of acid. Look at the diagram of Tom’s

experiment.

a Is a chemical reaction taking place? Explain your answer.

.........................................................................................................................

(1)b Give one other observation that would show that a chemical reaction is

taking place.

.........................................................................................................................

(1)

End of Unit test


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a Which box could represent a mixture of iron and sulfur?

.........................................................................................................................

(1)b Which box could represent a compound?

.........................................................................................................................

(1)c What is the name of the compound formed by heating iron with sulfur?

.........................................................................................................................

(1)d Could a magnet be used to separate the iron from box ‘a’?

.........................................................................................................................

(1)e Could a magnet be used to separate the iron from box ‘b’?

.........................................................................................................................

(1)

4 The temperature line on the next page shows temperatures between –10 °C and +100 °C.

a i The melting point of the element caesium is 29 °C. Label the melting point of caesium on the temperature line.

(1)ii Complete the following sentence:

When caesium melts it changes state from a .................. to a ..................

(1)b Label on the temperature line the melting point and the boiling point

of water.

(2)



iron sulfur box a box b


c Could the melting point of butter be marked on the temperature line? Explain your answer.

(2)

5 Look at the table below, which shows the melting points and boiling pointsof some elements.

Room temperature is 25 °C.Name two elements shown in the table that are

a solids at room temperature

.........................................................................................................................

(2)


Element Melting point °C Boiling point °Cbromine –7 +59iodine +114 +184radon –71 –62mercury –39 +357iridium +2410 +4130fluorine –220 –188

+100

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b liquids at room temperature

.........................................................................................................................

(2)c gases at room temperature

.........................................................................................................................

(2)

6 The diagram below shows the particles that make up distilled water.

a Which of the following options best describes distilled water?Tick one box.

Distilled water is an element.Distilled water is a mixture.Distilled water is impure.Distilled water is a compound.

(1)b A spatula of salt is dissolved in the distilled water. Which of the following

statements best describes what happens to the boiling point of this substance compared with pure water? Tick one box.

The boiling point will stay the same.The boiling point will increase slightly.The boiling point will decrease slightly.

(1)c The distilled water with the salt dissolved in it is then cooled. Which of

the following statements best describes what happens to the freezing point of this substance compared with pure water? Tick one box.

The freezing point will stay the same.The freezing point will increase slightly.The freezing point will decrease slightly.

(1)

Total marks: 25


water molecule


Extension question

7 Helen has been given a sample of an unknown chemical labelled ‘X’. Atroom temperature ‘X’ is a liquid. As Helen cools ‘X’ using an ice/salt mixtureit freezes to form a solid. Helen’s results are recorded below.

a Plot a graph to show Helen’s results (put time on the x axis and temperature on the y axis).

(3)b What is the freezing point of ‘X’?

.........................................................................................................................

(1)c Is ‘X’ a mixture? Explain your answer.

.........................................................................................................................

(1)


time (mins) 0 1 2 3 4 5 6 7 8 9 10temperature of ‘X’ (°C) 25 22 19 16 16 16 16 14 12 9 6



Text answers

1 Copper oxide, CuO, 1 atom of copper combined chemically with 1 atom of oxygenFluorine, F2, 2 atoms of fluorine per moleculeHelium, He, 1 atom of helium per moleculeCalcium carbonate, CaCO3, 1 atom of calcium combined chemically with 1 atom of carbon and 3 atoms of oxygen

2 Fluorine and helium are elements; copper oxide and calcium carbonate are compounds

3 a Hydrogen + oxygen � waterb Hydrogen and oxygen are gases at room temperature but water is a

liquid4 Megan can see bubbles (of a gas) being produced.5 Colour change or temperature change6 Type of tea, type and amount of water, milk7 a Crystallisation

b Chromatographyc Filtrationd Distillation

10 a Iron/copperb Mercuryc Oxygen/nitrogen

12 a Silicon dioxide/lead sulfideb Water/ethanol/methanolc Hydrogen chloride/dinitrogen oxide

13 The alcohol methanol


a Science, politics, religionb Carbon dioxidec He studied carbon dioxide which is used to make cola fizzyd SO2 – one sulfur and two oxygen atoms per molecule; NH3 – one nitrogen

and three hydrogen atoms per molecule; N2O – two nitrogen and oneoxygen atoms per molecule

e To escape persecutionf As a man of strong beliefs and radical ideas


1 a Atomb Symbolc Compoundd Mixturee Formula

2 a F b F c T d T e T f F3 a compounds, points

b 0 (zero), 100 (one hundred)c mixtured up, down

Compounds and mixturesC

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ANSWERS


4

5 a Elements can be joined together to form compounds.b Elements can be represented using simple symbols.c Elements are made of only one type of atom.d Elements can be mixed together to form mixtures.

Worksheet answers

D1 Elements and compounds1 water – H2O – two atoms of hydrogen combined chemically with one atom

of oxygenoxygen – O2 – two atoms of oxygen joined togethermagnesium oxide – MgO – one atom of magnesium combined chemicallywith one atom of oxygensulfur – S8 – eight atoms of sulfur joined togethercopper carbonate – CuCO3 – one atom of copper combined chemically withone atom of carbon and three atoms of oxygenchlorine – Cl2 – two atoms of chlorine joined together

2 oxygen, sulfur and chlorine are elements; water, magnesium oxide andcopper carbonate are compounds

D2 Particle models

D3 Observing reactionsSample answers are shown on pages 54–55 of the Pupil Book.

D4 Boiling points of pure and salty water1 Pure water boils at 100 °C, while salty water will boil at a slightly higher

temperature.2 If salt is added to the water to form a mixture the salt particles will

intermingle with the water molecules. This means that even when a watermolecule gains enough energy to turn into a gas and escape, it may wellcollide with a salt particle as it tries to leave the beaker and will beprevented from escaping. Water molecules need more energy to escape, sothe boiling point of salty water will be higher than the boiling point of purewater.

D5 Investigating a pure and an impure liquid1 ‘a’ is salty water, ‘b’ is distilled water.2 The boiling point of ‘b’ is 100 °C so it must be the pure, distilled water. The

boiling point of ‘a’ is slightly higher so it must contain impurities.

copper

1 2 3

oxygen

nitrogen

copper

oxygen

Chapter 4 Answers

iron

a b c

sulfur

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3 Evaporate the water and look for salt crystals; find the freezing points of theliquids; taste; any suitable suggestion.


1 atom (1)compound (1)mixture (1)

2 a yes, bubbles are seen (1)b temperature change/colour change/new smell (1)

3 a a (1)b b (1)c iron sulfide (1)d yes (1)e no (1)

4 a i mark at 29 °C (1)ii solid to a liquid (1)

b mark at 0 °C (1) and 100 °C (1)c No, it is a mixture (1); mixtures melt over a range of temperatures (1)

5 a iodine (1) iridium (1)b bromine (1) mercury (1)c radon (1) fluorine (1)

6 a Distilled water is a compound (1)b The boiling point will increase slightly (1)c The freezing point will decrease slightly (1)

Total marks: 25

Extension answers

7 a suitable axes (1)points correctly plotted (1)line connecting points (1)

b 16 °C (1)c No, it melts/freezes at one specific temperature (1) OR no, it does not

melt/freeze over a range of temperatures (1)




Chapter 4 Answers

Pupils should be familiar with the following ideas:• Air contains carbon dioxide, oxygen and other gases• Smaller molecules such as glucose are produced from larger ones in digestion• The heart pumps blood to circulate it through the body• Cells are organised into tissues and tissues can form organs• Breathing varies according to the body’s needs

5 Respiration

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AlveoliArteriesBlood vesselsBronchiBurnCapillaries

Chemical potential energy

Circulatory systemDeoxygenatedDiffuseEmphysema

EnergyGas exchangeGlucoseHeartLungsOxygenated

PumpRespirationSmall intestineTracheaVeins

In this topic pupils should learn:• How cells are supplied with the materials they need for respiration• How cells in animals and plants release energy• That the process of respiration is similar in all cells• The word equation for respiration• That blood is pumped round the body by the heart, and flows through blood

vessels • What arteries, capillaries and veins do• That blood picks up oxygen from the lungs, where it also gets rid of carbon

dioxide• That the lungs are made of millions of tiny alveoli

Learning checklist

Links

9HRS

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Unit Title7F Simple Chemical Reactions7I Energy Resources8A Food and Digestion9B Fit and Healthy


CH A P T E R

5

T I M I N G


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LiteracyThere is a literacy activity on early beliefs about blood circulation in the PupilBook.

5 Respiration

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Most pupils

Scientific enquiry• Describe an earlier model of circulation, indicating how it does not match

present-day evidence• Explain why control experiments and sample size are important when

investigating living organisms• Make appropriate observations, recording them accurately and identifying

patterns in data obtainedLife processes and living things• Describe the role of blood in transporting carbon dioxide from, and oxygen to,

the lungs• Explain why tissues need a good blood supply• Describe aerobic respiration as a reaction with oxygen• Describe some effects of an inadequate oxygen supply• Describe and explain differences between inhaled and exhaled air• Identify similarities in aerobic respiration in plants and animals


Scientific enquiry• Recognise that ideas about circulation have changed• With help, identify variables relevant to a question• Make observations and recognise patterns in dataLife processes and living things• Recognise that oxygen is needed for aerobic respiration• Recognise that oxygen and glucose are transported in the blood• Describe differences between inhaled and exhaled air


Scientific enquiry• Describe and explain some of the evidence leading to present-day ideas about

how and why blood circulatesLife processes and living things• Represent the process of aerobic respiration as a word and/or symbol equation• Identify similarities of aerobic respiration with the burning of fuels• Describe the features of alveoli and explain how damaged alveoli result in less

gas exchange

Learning outcomes



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Energy from foodPupils will all know that we need oxygen to stay alive, and the opening of thischapter introduces the idea that we need oxygen to provide us with energy.Pupils can then link this with their knowledge that food, too, gives them energy.Glucose is introduced as an excellent quick energy source, which leads on to therespiration equation.

This line of thought requires thinking back to several topics covered earlier:Energy resources and Simple chemical reactions from Year 7 (Pupil Book 1, Chapters5 and 6), and Food and digestion from earlier in Year 8 (Pupil Book 2, Chapter 3).It is worth taking some time to ensure that pupils have a sound understanding –at a simple level – of the concepts of energy transfer and of chemical reactionssince, without these, respiration can make no sense at all.

The demonstration of Worksheet E1, Energy from icing sugar, may help pupils tolink what they know about getting energy from fuels with the way in whichenergy can be obtained from foods. Icing sugar is actually a mixture of finelyground sucrose and corn starch, but there is no need for pupils to know this, andthey could simply equate it with glucose.

The term ‘aerobic respiration’ has purposely been avoided. It is suggested that atthis stage pupils assume that respiration always requires oxygen. Anaerobicrespiration will be introduced at KS4 and, until then, there is no point in usingthe term ‘aerobic’ in this context. (However, you might like to describe ‘aerobicexercise’, in which breathing rate increases to supply more air to the lungs andhence more oxygen to the tissues.) The important concept to emphasise here isthat respiration is a chemical reaction that occurs in every living cell and whichreleases energy from food substances. Do ensure that it is not confused with‘breathing’.

Worksheet E2, Detecting respiration in living organisms: looking for carbon dioxide,should help pupils to understand that all living things – plants as well as animals– respire. It is useful to get this idea firmly installed at this stage, beforephotosynthesis is introduced in Year 9. Germinating seeds are a good example touse, as they do not photosynthesise and therefore won’t confuse the results. It issuggested that hydrogencarbonate indicator is used instead of lime water, as it isvery sensitive to the small pH changes produced by changes in carbon dioxideconcentration, and will therefore give more rapid results. Before use, thehydrogencarbonate indicator should be constantly aerated with normal air, toensure that it is red when the pupils use it. You may be able to get results withinone lesson, but it may be necessary to leave the apparatus a little longer.

Worksheet E3, Detecting respiration in living organisms: looking for a temperaturerise, once again uses germinating seeds. Over time, the carbon dioxide that theyproduce will collect at the bottom of the container and may prevent the seedsfrom getting enough oxygen. The classic way of doing this demonstration is to useThermos flasks supported upside down (to allow carbon dioxide to escape) with athermometer inserted through the mouth of the flask. However, this seems tointroduce a level of mystery that can confuse some pupils, and it may be betterto use transparent containers so that pupils can see what is going on.

Worksheet E4, Investigating the rate of respiration, provides an opportunity tobuild on a technique already used (in Worksheet E2) to plan and carry out asimple investigation. If you have thermostatically controlled water baths, pupils



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could stand their tubes in these to achieve different temperatures. If you don’thave water baths, or have only one or two, pupils could keep one tube in abeaker of crushed ice, another in a fridge and another at room temperature.

If pupils have already done Worksheet E2, they should already have a roughidea of how long any colour changes will take, and they can use this to decidehow often they will check the colour of the indicator. Their design should includesuitable controls, such as a tube of dead peas (ideally these should be sterilised,so that there are no respiring microorganisms present), kept at each temperature.

Transporting glucose and oxygen to cellsThis section covers the concept of the blood being pumped around the body bythe heart. It flows in vessels. Pupils should learn that the blood goes to the lungsand then back to the heart, and then around the body and back to the heartagain. There is no need for them to learn the term ‘double circulatory system’ atthis stage.

Nor is there any need for detailed coverage of the structure of the heart andblood vessels, or of the composition of blood, all of which will be dealt with atKS4. However, it is useful to know that there are three types of blood vessels.

The Literacy activity, Early beliefs about blood circulation, and Worksheet E5, Thediscovery of the blood circulation, can be used to help pupils to understand justhow slow progress has been in our understanding of such a basic idea.

These two activities give only a very basic outline of some of the maindevelopments, and further research by pupils can help to flesh out these barebones. In particular, it would be interesting for them to find out more about thebackground against which each of the people worked and thought, including thereligious dogma of the time. This may help pupils to understand the willingnessof even highly intelligent people blindly to accept ideas that were completelyunsupported by any observational or experimental evidence. The peopledescribed are some of the ‘main players’, but they are by no means the onlyones, and others could be researched, for example Erasistratus, Avicenna (IbnSina), Aristotle and Withering.

The lungs and gas exchangeIf you can obtain a set of lungs from a local butcher, pupils will enjoy looking atthese. They should be able to see the trachea and bronchi, and feel the soft,spongy texture of the lungs for themselves. Care must be taken with hygiene;don’t let pupils touch the lungs except under supervision, and ensure thateverything that comes into contact with them (including fingers) is thoroughlywashed immediately after the demonstration has finished. However, any dangersare no greater than those of handling fresh meat.

At this stage, it is suggested that you concentrate only on the gas exchangesurface – that is, the alveoli and their close relationship with the blood capillaries.There is no need to mention breathing or ventilation, which will be dealt with at KS4.

Worksheet E6, Comparing the carbon dioxide content of inspired air and expired air,should help pupils to appreciate that both types of air contain at least somecarbon dioxide. It is a very common misconception that expired air ‘is’ carbondioxide. It is possible to demonstrate the concentration of oxygen in expired andinspired air using alkaline pyrogallol, but this is an unpleasant substance to use,and, even more importantly, the demonstration is not a clear and easy one formost Year 8 pupils to understand.

5 Respiration



Another possibility is to burn a candle in inspired air and in expired air, andcompare the time taken for it to go out. You could also ask pupils to compare themoisture content of inspired and expired air (using blue cobalt chloride paper)and the temperature (breathing onto a thermometer) to build up a fuller pictureof the differences between them.

The description of lung damage caused by smoking is confined to emphysema,because this links directly with gas exchange. Smoking and its effects are coveredmuch more fully in Year 9.

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Energy from foodPupils will already know something about energy transfers, food as fuel andsimple chemical reactions. Questions and answers can help to draw thisinformation from them, and help them to make links and predictions.You could ask pupils for their ideas on some of the following:

• What is absorbed food used for in the body?• How does absorbed food get to all parts of the body?• What is energy?• What is in high-energy drinks?• Is a high-energy drink a fuel?• How do we get energy from fuels?• How do you think we get energy from fuels inside the body?• What do muscles need to help them to work?• Do we make heat inside the body?

Worksheet E1 Energy from icing sugarTo make this demonstration work well, you'll need to try it out beforehand.Success is more likely if:• you use a relatively small cardboard ‘tin’, such as a milk powder, custard

powder or cornflour container;• the candle has a long wick so that it burns with a strong flame;• the hole for the tubing is a good, tight fit, and is level with the hottest part of

the flame;• you use plenty of icing sugar and blow it into the flame with a quick, sharp

puff;• the lid is on neither too tightly nor too loosely.

If all goes well and pupils are interested, you could discuss the importance of theicing sugar being in the form of a fine powder, allowing more sugar molecules to



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be in direct contact with oxygen molecules. You could also try testing the airinside the tin for carbon dioxide, using lime water.

Worksheet E2 Detecting respiration in living organisms: looking for

carbon dioxideThis will be the first time pupils have met hydrogencarbonate indicator. You coulddo this investigation with lime water, but it will take longer to get results.Hydrogencarbonate indicator is actually a sensitive pH indicator, and the colourchanges are caused by the formation of a weak acid when carbon dioxidedissolves in it. The indicator should be freshly made up, and should have aircontinuously bubbled through it until it is to be used. This will keep it red. Ascarbon dioxide dissolves in it, it gradually becomes more and more yellow. Thereis no sharp end-point. You may like to have samples of red and yellow indicatoron display for pupils to compare their results against.

(Where carbon dioxide is present in even lower concentrations than in air, theindicator becomes purple. It will also do this if lime water gets mixed with it –which may well happen if you have some pupils using lime water and someusing hydrogencarbonate indicator, or if tubes are not thoroughly cleaned before re-use.)

Some pupils will make a fuss about handling maggots. The best way to deal withthis is to let others handle the maggots instead. Vigilance is required to preventany mishandling. Live maggots can be obtained from pet shops and fishingshops, and will stay healthy for a couple of days if kept in a closed container withsawdust. After that, they are likely to pupate.

Worksheet E3 Detecting respiration in living organisms: looking for a

temperature riseIt is suggested that a fairly large number of peas be used, to produce atemperature rise which can be measured. Ensure that all pupils can read athermometer scale. You may be lucky and get results within the lesson, but if not,then try to arrange for pupils to return to read the temperature later in the day. Ifavailable, you could set this up using a data-logger to measure and record thetemperatures over a 24-hour period.

Worksheet E4 Investigating the rate of respirationCheck that pupils understand the term ‘rate’ before asking them to draw up theirplans. You could arrange pupils in mixed-ability groups or in groups of differingability – the latter arrangement can push weaker pupils into having to make acontribution rather than relying on others. They will all be familiar with thetechnique they used on Worksheet E2, so can concentrate on thinking aboutvariables and how to control them, and on what to measure.

It is not at all certain that all groups will obtain the expected results for thisinvestigation, and pupils should be encouraged to accept this if it happens, andnot to say: My experiment didn’t work. Help them to suggest reasons for theresults that they did obtain, and not to be worried if it is not possible to draw afirm conclusion from their experiment.

Transporting glucose and oxygen to cellsThis topic requires some knowledge of the structures of the human circulatorysystem and gas exchange system, together with some specialist vocabularyassociated with it. Pupils will need to make an active effort to learn these factsand terms.

5 Respiration



Worksheet E6 Comparing the carbon dioxide content of inspired air

and expired airThe apparatus suggested here is neat and easy to use, but it can be difficult forpupils to understand how and why expired air bubbles through one tube andinspired air through the other. Take some time to help them with this before theyactually do the experiment.

There is no real danger to them if they swallow hydrogencarbonate indicator, butall the same, it is wise to tell them that this is harmful, and to ensure that theybreathe gently in and out through the tube, rather than blowing and sucking.

The indicator will probably change colour in the ‘expired air’ tube after only afew breaths. This shows that expired air contains more carbon dioxide thaninspired air. Many pupils will wrongly think their results show that there is carbondioxide in expired air but not in inspired air.

You could extend this investigation to compare the moisture content of inspiredand expired air, using blue cobalt chloride paper. Pupils can wave this around inthe air (use forceps to hold it, as even the cleanest fingers have moisture onthem) to test inspired air, and breathe gently over it (not lick it or put it into theirmouths) to test expired air. The presence of water changes the colour from blueto pink. Homemade cobalt chloride paper, kept in a desiccator, usually worksmuch better than commercially available products.

However, it is wrong to suggest that the reason why expired air contains morewater than inspired air is because water is a product of respiration. The additionalmoisture in expired air has evaporated from the moist surfaces of the alveoliinside the lungs.


Sc1

Scientific Enquiry

1c, 2d, 2e, 2g (partially), 2i (partially), 2j, 2k, 2m

Sc2


2c, 2d, 2i, 2j, 2k,2l

Sc3


Sc4

Physical Processes

5a (partially)



What I have learnt

Respiration


Bronchi

Deoxygenated

Heart

Diffuse

Oxygenated

Capillaries

Respiration

Trachea

Gas exchange

Emphysema

Arteries

Lungs

Pump

Blood vessels

Veins

Circulatory system

Burn

Energy

Small intestine

Alveoli

Glucose

Chemical potentialenergy


• I know where cells get the materialsthey need for respiration

• I know that cells in animals andplants release energy

• I know that the process of respirationis similar in all cells

• I can write the word equation forrespiration

• I know that blood is pumped roundthe body by the heart

• I know what arteries, capillaries andveins do

• I know that blood picks up oxygenfrom the lungs

• I know that the lungs are made ofmillions of alveoli

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CHECKLIST

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Lesson Focus Pupil Book 2 pp. 67–69Energy is obtained from food when it reacts with oxygen inside cells

ExpectationsMost Pupils Know that energy can be obtained from glucose by combustion;

know that, inside cells, glucose is combined with oxygen inrespiration, and that carbon dioxide is produced and energy isreleased.

Less Able Pupils Know that energy can be obtained from glucose by burning it, andthat a similar reaction takes place inside cells.

More Able Pupils All the above, plus understand the similarities and differencesbetween combustion and respiration, and link this to theirknowledge of simple chemical reactions, food and digestion andenergy resources.



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Demo: Worksheet E1 Energy fromicing sugarA cardboard ‘tin’ with a lid (e.g. custardpowder tin) with a hole in the side atcandle flame levelA short length of rubber tubing which fitstightly in the holeA short candle which sits firmly in thebottom of the tinMeans of lighting the candleIcing sugar and a spatula to help to loadit into the tubing at the tin end (seediagram on page 168)

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10 In and register. More able pupils will find it easier to remember Pupils recall, and make links between, their earlier work on.Starter. Use the photograph on page 67 in the Pupil Book to begin a discussion earlier work and to make links between their fuels, on chemical reactions, on energy resources and on food on why we need oxygen. Use Q and A to help pupils to remember what they previous work on food, fuels, energy resources and digestion. know about food as fuel, and how we get energy from fuels by combustion. and simple chemical reactions. They know that glucose is a sugar which can be used as an Introduce glucose as a sugar (carbohydrate), explain that it is the quickest source Less able pupils will be able to make some of energy source.of energy for our bodies, and introduce the idea that it can be burnt like a fuel these links.to release energy.

15 Development. Distribute Worksheet E1 Energy from icing sugar. Show pupils Pupils see for themselves that glucose can combine with the apparatus and explain what they are going to see. Carry out the oxygen to release energy.demonstration. Discuss the answers to the questions. Repeat the demonstrationif pupils have enjoyed it.

10 Ask pupils to answer the questions on Worksheet E1 in their workbooks. Less able pupils will need guidance to help them Pupils reinforce the idea that a chemical reaction between to answer the questions. glucose and oxygen produces carbon dioxide and releases

energy.

10 With the class, discuss question 1 on page 68 in the Pupil Book. Then ask them More able pupils will volunteer answers. Pupils reinforce the links between their knowledge of food, to write down the answers in their workbooks. digestion and energy supply for the body.

5 Plenary. Using the diagram on page 69 in the Pupil Book to support More able pupils will make the link between Pupils understand that respiration is a chemical reaction understanding, explain to the class that glucose is combined with oxygen inside combustion and respiration, and understand the similar to combustion, which takes place inside cells.cells in a gentle way, and that this chemical reaction is called respiration. difference between them. Less able pupils will

probably be able to make this link, but may continue to think that glucose is ‘burnt’ inside cells.



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Lesson Focus Pupil Book 2 p. 69Detecting carbon dioxide produced by respiring organisms

ExpectationsMost Pupils Use hydrogencarbonate indicator to detect the production of

carbon dioxide, and understand that the results of theirinvestigation indicate that plants and animals, but not non-livingthings, respire. Write a definition of respiration. Show respect forliving animals.

Less Able Pupils Use hydrogencarbonate indicator to detect the production ofcarbon dioxide, and know that carbon dioxide is produced inrespiration. With help, write a definition of respiration. Showrespect for living animals.

More Able Pupils All the above, plus suggest methods of detecting respiration.



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Worksheet E2 Detecting respiration inliving organisms: looking for carbondioxidePer group:Four test tubes (or boiling tubes), eachfitted with a gauze platformAccess to well-aerated hydrogencarbonateindicator solutionClean dropper pipetteTest tube rack or beakerAccess to: live maggots; live, germinatingpeas; dead peas; small beadsBlunt forceps or other means of handlingmaggots

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10 In and register. More able pupils will remember these concepts Pupils recall what respiration is and where it takes place, and Starter. Use Q and A to help pupils to recall their work from Lesson 1 and to and facts, and will volunteer information. They are able to define it.arrive at these ideas: respiration takes place in living cells and involves a will include all relevant facts in their definition. chemical reaction between glucose and oxygen, in which carbon dioxide and Less able pupils will have more difficulty in writing water are formed and energy is released. a complete definition and will need some help Ask pupils to write down a definition of respiration in their workbooks. with this.

10 Development. Ask pupils to suggest how you might detect whether something Pupils reinforce their knowledge that respiration is a chemical is respiring or not. If answers relate to breathing in humans, use this to reinforce reaction, and understand that you can tell it is happening by the idea that all living things respire (including plants) and that breathing is not detecting the production of carbon dioxide or a temperature the same as respiring. rise. They recall their knowledge of the test for carbon Use questioning and the word equation for respiration to lead them (if dioxide. necessary) towards the idea of detecting carbon dioxide and temperature rises. Ask them how they could detect the presence of carbon dioxide.

5 Distribute Worksheet E2 Detecting respiration in living organisms: looking Pupils know how hydrogencarbonate indicator can be used to for carbon dioxide. Talk through this with pupils, including the need for respect test for carbon dioxide. They know that they should have for the animals involved. Demonstrate the colour changes of hydrogencarbonate respect for living organisms. indicator.

20 Ask pupils, in groups, to follow the instructions on the worksheet. Less able pupils will require help in constructing a Pupils detect the carbon dioxide produced by living organisms.suitable results table.

5 Plenary. Discuss their results with the class. Allow any groups who have not Pupils understand that both animals and plants respire. managed to get results to use those from another, successful group.

Homework: Complete steps 3 and 4 on Worksheet E2.


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Lesson Focus Pupil Book 2 p. 69Respiration produces a rise in temperature which can be detectedPlanning an investigation to compare the rate of respiration at different temperatures

ExpectationsMost Pupils Measure a difference in temperature between respiring and non-

respiring organisms. Contribute substantially to a plan forcomparing rate of respiration at different temperatures and predictwhat the results may be.

Less Able Pupils Measure a difference in temperature between respiring and non-respiring organisms. Contribute to a plan for comparing rate ofrespiration at different temperatures.

More Able Pupils All the above, plus appreciate the difficulties of determining anend-point and suggest ways of dealing with this.



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Worksheet E3 Detecting respiration inliving organisms: looking for atemperature risePer group: Two conical flasks; cotton wool to make‘stoppers’Insulating material for the flasksTwo thermometersBoiled (sterilised) peasLive germinating peasOptional: Thermos flask

Worksheet E4 Investigating the rate ofrespirationOne sheet per pupil (planning exercise inthis lesson)Optional: Prepare a proforma on whichless able pupils can write their plan

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5 In and register. More able pupils will remember how to detect Pupils reinforce their knowledge of how to detect respiration. Starter. Use question and answer to remind pupils of how they detected respiration by looking for carbon dioxide, and will respiration by testing for carbon dioxide. Introduce the idea of detecting suggest that a rise in temperature could also be respiration by looking for a temperature rise. used as an indication that respiration is happening.

10 Development. Distribute Worksheet E3 Detecting respiration in living Pupils know how to deal with a mercury-in-glass organisms: looking for a temperature rise. With the class, look through the thermometer safely. They use thermometers to detect a worksheet. Check they know how to use and read a thermometer. temperature rise as an indication of respiration. Safety: Check that pupils know what to do if a mercury-in-glass thermometer is broken. Ask pupils, in groups, to set up the apparatus and to leave it in a safe place.

10 Arrange pupils in mixed ability groups. Distribute Worksheet E4 Investigating More able pupils are likely to lead this Pupils use knowledge of a technique to plan an the rate of respiration. Ask each group to discuss how they will tackle this task. discussion. Less able pupils may not appreciate investigation. They know that, to measure a rate, you

the need to measure time if they are need to measure time. investigating rate.

10 Plenary. Ask two or three groups to report on their plans (they may need to More able pupils will remember the difficulty of Pupils clarify their ideas for their experimental plan by appoint a spokesperson to do this). Encourage other groups to ask questions to defining and timing colour changes with attempting to communicate them to others. They consider the clarify the plans. Draw out the idea of using more than one sample at each hydrogencarbonate indicator, and will suggest benefits of using replicates, and the problems of determining a temperature and averaging results. Point out the difficulty of deciding exactly ways of dealing with this. precise end-point. when a colour change has taken place, and ask for suggestions about how to standardise these decisions. Ask pupils to predict what the results might be.

15 Ask each pupil to write down the plan for the investigation of Worksheet E4 Less able pupils can be given a proforma to fill in which they will carry out next lesson, including drawing a results chart ready to for their plan.fill in.At end of lesson, read temperatures in the apparatus from Worksheet E3.

Homework: Write up the investigation on Worksheet E3, including answers to part 4. If not done, finish writing up the plan and results chart for Worksheet E4.


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Lesson Focus Pupil Book 2 p. 69A planned investigation into how temperature affects the rate of respiration

ExpectationsMost Pupils Carry out an investigation which successfully measures a difference

in the rate of respiration at two temperatures, controlling mostvariables (mass or number of peas, volume of indicator). Makesome attempt to interpret their results in terms of knowledge ofparticle theory and effect of temperature on enzymes.

Less Able Pupils Carry out an investigation which measures a difference in the rateof respiration at two temperatures. Appreciate the need to controlat least one variable. With help, make a simple interpretation oftheir results.

More Able Pupils All the above, plus appreciate the limits of their experimentalmethod and suggest ways of improving this.



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Worksheet E4 Investigating the rate ofrespiration; plan prepared in Lesson 3Spare copies of Worksheet for pupils whohaven’t theirsPer group:Apparatus as for Worksheet E2 (seeLesson Plan 2), but dead and germinatingpeas only – no beads or maggotsStopwatch or stopclockMeans of measuring volumes of about 10 cm3, for example syringes Access to top pan balance (if they wantto measure the mass of the peas)Options for a wide temperature range:Thermostatically controlled water bath;beaker of crushed ice; beaker to put infridge; beaker at room temperature

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30 In and register. More able pupils will be more aware of the need Pupils carry out their plan, making modifications to improve Starter. Arrange pupils in the same groups as last lesson. Check that each pupil to make small changes to their method to improve it. has a copy of Worksheet E4 and their plan, and understands the design of the their plan. Less able pupils may need some investigation. support and guidance to achieve a result. Development. Ask groups to carry out their investigation, making notes on their plans if they decide to make any changes.

10 Plenary. Debrief groups on their findings. Display results on the board, Less able pupils will need encouragement and Pupils appreciate the fact that their results cannot be precise interactive white board or OHP. Use Q and A to draw out possible explanations guidance to help them to appreciate the because of the difficulty of determining the exact time of any for these results, referring to their knowledge of particle theory (from Year 7) shortcomings of the method. More able pupils colour change in the indicator. They interpret their results in and the effect of very high temperatures on enzymes (Chapter 3). Discuss will offer explanations for their results. terms of their previous knowledge.reliability: How safe do they feel their decisions were on when the colour change happened?

10 Complete the work on Worksheet E4 by writing a brief conclusion and an Less able pupils can be given an outline sheet evaluation/discussion. with questions to prompt them. More able pupils

can write their conclusion and evaluation/discussion with no further guidance.

Homework: Think about, and research if possible, how oxygen and glucose are delivered to respiring cells in a human.


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Lesson Focus Pupil Book 2 pp. 69–71The circulatory system



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Circulatory system diagramUnlabelled diagram for pupils to label

Historical ideas about human bloodcirculationPictures, OHTs, video clips and any otheravailable material to illustrate the workand times of Hippocrates, Galen and Ibn-al-Nafis (see also Teacher Notes:Transporting glucose and oxygen to cells)

ExpectationsMost Pupils Understand that blood carries glucose and oxygen around the

body. Can label a simple diagram of the circulatory system. Canuse some correct terminology associated with this. Know that earlyand long-held beliefs about the circulatory system were not basedon experiment.

Less Able Pupils Understand that blood carries glucose and oxygen around thebody. Can label some structures on a simple diagram of thecirculatory system. Know that early beliefs about the circulatorysystem were incorrect.

More Able Pupils All the above, plus appreciate the double nature of the circulatorysystem, in which blood flows through the heart twice on onejourney around the body. Use terminology with confidence.Appreciate why early and incorrect beliefs about the bloodcirculation were unquestioned for so long.

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10 In and register. More able pupils will have discovered more about Pupils understand that the circulatory system delivers glucose Starter. Ask pupils to volunteer information about what they have found out the circulatory system, and will volunteer and oxygen to cells. They learn the meanings of the terms about how glucose and oxygen are delivered to cells. Use their ideas, and information. ‘artery’, ‘vein’ and ‘capillary’, and understand that the heart is diagram on page 70 of the Pupil Book, as starting points to discuss with the a pump which keeps blood moving through blood vessels. class the structure of the circulatory system and the fact that oxygen and glucose are transported to the cells in the blood. Introduce the terms ‘artery’, ‘vein’ and ‘capillary’, ‘oxygenated’ and ‘deoxygenated’. Ask pupils to suggest where oxygen and glucose get into the blood.

5 Development. Provide pupils with an unlabelled diagram of the circulatory More able pupils could try to do this without Pupils have a record of the structure of the circulatory system. system, and ask them to label it. looking at the diagram in the book, and then

check their labels.

15 Ask pupils to answer in their workbooks questions 4 and 5 on page 71 of the Less able pupils may have time to answer only Pupils reinforce their understanding of the circulatory system. Pupil Book. Discuss their answers with them. some of these questions.

10 Plenary. Ask one or two pupils to read aloud the text of the Literacy activity Pupils know that early beliefs about the blood circulation were Early beliefs about blood circulation on page 75 of the Pupil Book. not based on experiment. Use stimulus material to help the class to understand some of the background to the work of these people. Discuss how slow people were to investigate the truth about how blood flows around the body, and why progress was so slow.

10 Extension: With the class, discuss the meanings of the words in question a of the Literacy activity. Ask them to make a drawing, or write a description, of a person with each of these temperaments.

Homework: Complete the answers to questions 4 and 5, and also 6 if time, from page 71 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 72–73Structure of the lungs and gas exchange

ExpectationsMost Pupils Know the structure of the gas exchange system, and understand

how oxygen and carbon dioxide are exchanged between blood andalveoli. Know that early and long-held beliefs about the circulatorysystem were not based on experiment.

Less Able Pupils Know the appearance of lungs, and know that this is where oxygenenters the body and carbon dioxide leaves it. Know that earlyideas about circulation were incorrect.

More Able Pupils All the above, plus use particle theory to explain gas exchange.Appreciate why early and incorrect beliefs about the bloodcirculation were unquestioned for so long.



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Demo: Lungs and their structureA set of lungs (for example pig or sheep)obtained from a butcherLarge board or container for displayingtheseFine rubber gloves if requiredAccess to warm water and soap forwashing hands

Worksheet E5 The discovery of theblood circulationOne sheet per pupil (paper exercise)Material to support and illustrate this, forexample illustrations of the peoplementioned, video clips

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15 In and register. Pupils know the appearance and texture of lungs and trachea, Starter. Demonstrate the appearance and structure of pig or sheep lungs. and learn terminology associated with lung structure. Emphasise safety: wash hands thoroughly if the lungs are touched. Help pupils to identify the windpipe (trachea) and feel their own necks to find their windpipe (the cartilage rings can easily be felt). Help pupils to appreciate thespongy texture of the lungs, and that their pink colour results from the blood inside capillaries (too small to see).

10 Development. Using the diagrams on pages 72–73 of the Pupil Book, discuss the More able pupils will volunteer descriptions of Pupils reinforce their knowledge of particle theory and internal structure of the lungs and how gas exchange takes place. Revise the diffusion, using their knowledge of particle theory. diffusion. They understand how gas exchange takes place meaning of the term ‘diffusion’. between the lungs and the blood.

10 Ask pupils to answer in their workbooks question 7 on page 73 of the Pupil Pupils use their knowledge of oxygen uptake to predict how Book, and then to make a copy of the diagram on page 73. carbon dioxide loss occurs, and have in their notebooks a

record of how gas exchange takes place.

15 Plenary. Distribute Worksheet E5 The discovery of the blood circulation. Pupils learn something of the early history of understanding of Ask one or two pupils to read the text aloud, stopping for discussion and the circulatory system.questions after each paragraph. Use support material (for example illustrations) to help to give an idea of the life and times of the people mentioned.

Homework: Draw a time line using the information from the Literacy activity, Early beliefs about blood circulation, page 75 of the Pupil Book, and Worksheet E5, to illustrate the history of our understanding of thecirculatory system.


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Lesson Focus Pupil Book 2 pp. 73–74Comparing the composition of inspired and expired airEmphysema



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Worksheet E6 Comparing the carbondioxide content of inspired air andexpired airPer group:As illustrated on the worksheet: twoboiling tubes with bungs; glass tubing;rubber tubing which must be cleaned anddisinfected before and after useMeans of supporting apparatusHydrogencarbonate indicator solution,freshly made and well aerated (limewater could be used instead)Dropper pipette or small bottles fortransferring indicator into the boilingtubesOptional: candle, blue cobalt chloridepaper to compare moisture content

Emphysema discussionIllustrations, video clips, leaflets tosupport discussion

ExpectationsMost Pupils Investigate the difference in carbon dioxide concentration in

inspired and expired air and interpret results correctly. Know andrecord the difference in composition between inspired and expiredair. Know the term ‘emphysema’, and are able to describe itscauses and effects.

Less Able Pupils With help, investigate the difference in carbon dioxideconcentration in inspired and expired air. Know and record thedifference in composition between inspired and expired air. Knowthe term ‘emphysema’.

More Able Pupils All of the above, plus use knowledge of respiration and gasexchange to predict correctly the difference in compositionbetween inspired and expired air.

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5 In and register. More able pupils will use their knowledge of gas Pupils use their knowledge to predict the differences between Starter. Referring to what they know about gas exchange, ask pupils to predict exchange, and of respiration, to predict differences. inspired and expired air.what differences there might be between the air they breathe in and the air they breathe out.

20 Development. Distribute Worksheet E6 Comparing the carbon dioxide Pupils who work quickly can also compare the Pupils know how to use hydrogencarbonate indicator to content of inspired air and expired air. Ask pupils to carry out the activities moisture content of inspired and expired air, using measure differences in carbon dioxide concentration in on this worksheet, and to answer the questions. cobalt chloride paper. inspired and expired air.

10 Discuss group results. Introduce End of chapter question 2 on page 77 of the More able pupils are more likely to remember Pupils make a record of the differences in composition Pupil Book and ask pupils to recall what they know about the composition of something about the composition of air. Less able between inspired and expired air. air. Ask someone who can remember this to provide the answer to part a, and pupils may need to be reminded that air is a then ask all pupils to write down the answer to this and to b and c in their mixture of several different gases, as well as the workbooks. relative proportions of these gases.

10 With the class, discuss the way that lung damage can cause breathing difficulties Pupils appreciate how lung damage can prevent enough (appreciate that some pupils may have relatives with emphysema or other oxygen getting into the blood. similar illnesses). Introduce the term ‘emphysema’, referring to the photographs on page 74 of the Pupil Book and other support material available.

5 Plenary. With the class, look at End of chapter question 1 on page 77 and ask Pupils revise the terminology associated with this topic. for volunteers to provide answers to part a.

Homework: Answer question 1 on page 77 of the Pupil Book. Revise respiration for the test.


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Lesson Focus Pupil Book 2 Chapter 5End of Unit test

ExpectationsMost Pupils Demonstrate secure knowledge and understanding of respiration

and the circulatory system.

Less Able Pupils Demonstrate some knowledge and understanding of respirationand the circulatory system.

More Able Pupils All the above, plus demonstrate good understanding ofexperimental design and interpretation of results.



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30 In and register. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the Distribute End of Unit test and ask pupils to answer this. correctly and will attempt the extension question. End of Unit test.

20 In pairs, allow pupils to choose and then answer either question 3 or question 4 Pupils reinforce their knowledge and understanding of one or on page 77 of the Pupil Book. more aspects of respiration, gas exchange and circulation.

Homework: Complete the description or poster (question 3 or 4). If time, answer the question not answered so far.


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Your teacher will demonstrate this to you.

This is the apparatus that will be used.

First the candle is lit. Then the lid is pushed onto the tin. Then the icingsugar is blown from the tube onto the candle flame.

E1 Energy from icing sugarCHAPTER

WORKSHEET1

5


1 Describe what happens when the icing sugar hits the flame.

2 Copy and complete this word equation for the reaction thattakes place inside the tin.

.................................... + oxygen � ................................ + water

3 Where does the oxygen come from?

4 Sugar contains a lot of chemical potential energy. Copy andcomplete this sentence to describe the energy changes thattake place inside the tin.

.............................. energy in the sugar is changed to

...................... energy and ....................................... energy.

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E2 Detecting respiration in

living organisms: looking for

carbon dioxide

CHAPTER

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5

When living things respire, they produce carbon dioxide:

glucose + oxygen � carbon dioxide + water

You are going to test some living things to see if they produce carbondioxide. If they do, this suggests they are respiring.

You have probably already used lime water to test for carbon dioxide. Nowyou can try a different test. This time, you can use a red liquid calledhydrogencarbonate indicator. This liquid:

• is red when there isn’t much carbon dioxide• is yellow when there is a lot of carbon dioxide.

1 Set up your apparatus like this:

2 Draw up a table and make a note of the colour of the hydrogencarbonateindicator in each tube. Ask your teacher for help if you are not sure howto do the table. Leave the tubes in a rack for a while. Then observe andrecord the colour of the hydrogencarbonate indicator again.

3 Record your results in the table. 4 Suggest explanations for the results in each tube.


Take GREAT carenot to harm theliving animals.You may not likemaggots verymuch (theyprobably don'tlike you, either)but they didn’tvolunteer forthis experimentand deserve tobe treated withconsideration.

When you havefinished, gentlytake themaggots out ofthe tube andreturn them totheir storagecontainer.

A B C D

plasticbeads

livegerminatingpeas

deadpeas

hydrogencarbonateindicator solution

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bung

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When respiration happens, the chemical potential energy in glucose ischanged into other forms of energy, including heat energy.

glucose + oxygen � carbon dioxide + waterchemical potential energy � heat energy

1 Set up your apparatus as in the diagram.

2 As soon as you have set up your apparatus, measure the temperature ineach flask, and record it. Then leave both flasks for a few hours.

3 Now measure the temperature in both flasks again, and record it. 4 Suggest an explanation for your results.

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E3 Detecting respiration in living

organisms: looking for a

temperature rise

CHAPTER

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E4 Investigating the rate of

respiration

CHAPTER

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You are going to plan and carry out an experiment to try to answer thisquestion:

Do germinating peas respire faster when the temperature is higher?

You can use apparatus like that in Worksheet E2. The faster the peas respire,the faster the hydrogencarbonate indicator will change colour.

Your teacher will give you some ideas about how you can keep the peas atdifferent temperatures.

You will need to make decisions about each of these things:

• What are you going to vary in your experiment? How will you do this?

• What are you going to keep the same in your experiment? How will you dothis?

• What are you going to measure? How will you do this?

• How many peas will you use?

• How will you record and display your results?

When you actually begin to do your experiment, don't be afraid to changeyour plans if you can see a better way of doing things.

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E5 The discovery of the

blood circulation

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Right up until the middle of the 17th century, student doctorswere taught the theories of Galen, who had lived nearly 1400years before. It was practically forbidden to question these ideasor to have any new ones of your own. No-one did anyexperiments to check whether or not they were right. It justwasn't the thing to do.

But in the 16th century, some brave physicians did begin toquestion Galen, and to do some investigations of their own.Vesalius was Belgian, and he lived between 1514 and 1554. Likeevery other student, he was taught Galen’s ideas. But Vesaliusdidn’t believe them. Illegally, he dissected human bodies andcould find no trace of the ‘pores’ that Galen had said allowedblood to flow from one side of the heart to the other.

Round about the same time, a Spanish physician called Servetus(1511–1553) discovered that blood flows to the lungs from theright side of the heart. Like Vesalius, he was living in a timewhen a few people were beginning to question the old ideasthat everyone was supposed to accept and believe. Hisquestioning went too far for the times, and he was eventuallyburnt to death because he had ideas that did not match the onesthat Christians were supposed to believe.

In Italy, Fabricius (1537–1619) carefully dissected veins. He foundthat they contained valves. But he got their function wrong. Hethought that the valves slowed the blood down so that thetissues would have plenty of time to take nutrients from it.

William Harvey was an English physician who lived between 1578and 1657. He dissected lots of mammals and examined theirhearts and blood vessels. He worked out that the blood in all theveins flowed towards the heart, the blood system was a one-waysystem, and that the valves in the veins helped to keep it goingone way.

Draw a time line, using the information on this worksheet andin Early beliefs about blood circulation on page 75 of the PupilBook, to show how ideas about the circulation of the blooddeveloped.

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Inspiration means ‘breathing in’. Inspired air is the air that you breathe intoyour lungs. This is ordinary air, the air that is all around you.

Expiration means ‘breathing out’. Expired air is the air that you breathe outof your lungs.

You are going to test inspired air and expired air for carbon dioxide, andfind out which of them contains more.

1 Set up your apparatus like this.

4 Keep breathing gently in and out until the indicator in one of the tubeschanges colour.

5 Carry on breathing gently in and out until the indicator in the other tubealso changes colour.

E6 Comparing the carbon

dioxide content of inspired air

and expired air

CHAPTER

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1 In which tube did the liquid change colour first?2 Was this the tube with the inspired air, or the tube with the

expired air bubbling through it?3 What do your results show about the concentrations of

carbon dioxide in inspired air and expired air? Choose one ofthese sentences:

A Inspired air contains more carbon dioxide than expired air.B Inspired air contains less carbon dioxide than expired air.C Inspired air does not contain any carbon dioxide.

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Tube BTube A

hydrogen-carbonateindicator solution

boiling tube

rubber tube 2 Write down the colour of theindicator in tube A and tube B.

3 Breathe gently in and out, throughthe rubber tube. Do not blow orsuck! Copy and complete these sentences:

As I breathed out, bubbles appeared

in tube .............................................. . So expired air was bubbling throughthis tube.

As I breathed in, bubbles appeared in

tube ................................................... . So inspired air was bubbling throughthis tube.


1 a Complete this word equation to show how respiration happens.

glucose + .............................. � carbon dioxide + ..................................

(2)b Name one liquid that you could use to test for carbon dioxide.

.........................................................................................................................

(1)c What colour is this liquid:

when there is very little carbon dioxide present? .......................................

when there is a lot of carbon dioxide present? ..........................................

(2)2 This diagram shows an alveolus and a blood capillary.

a On the diagram, draw one arrow to show the direction in which oxygen diffuses. Label the arrow O.

(1)b On the diagram, draw another arrow to show the direction in which

carbon dioxide diffuses. Label the arrow C.

(1)c The blood arriving at the lungs has come from the heart. Which side of

the heart has it come from? .........................................................................

(1)

End of Unit test

Respiration

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3 This diagram represents the circulatory system.

a On the diagram, label

• an artery• a vein• the muscle of the heart

Do this by drawing label lines – don't just write on top of the diagram!

(3)b Using a pencil, shade in all the oxygenated blood.

(3)



Left side of heart pumps bloodto all other organs and back

Right side of heart pumps bloodto lungs and back

digestive system

muscles

other organs

lungs

brain


4 Jane is running on a treadmill. Her heart is beating much faster than usual.

a Jane's leg muscles are using a lot of energy. Using the words respiration, oxygen and glucose, explain how they get their energy.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

(2)b Using your answer to a, explain why Jane's heart beats faster while she

is running.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

(3)5 In each of these groups of statements, only one is correct. Underline the

correct one in each case.

a Every living cell respires.Only animal cells respire.Plants don't respire.

(1)b Expired air does not contain any oxygen.

Expired air contains more carbon dioxide than inspired air.Inspired air does not contain any carbon dioxide.

(1)c Glucose is burnt inside your cells.

Glucose is combined with oxygen inside your cells.Glucose is combined with carbon dioxide inside your cells.

(1)



6 Pamir has smoked all his life. He is always coughing. His doctor has told him that many of his alveoli have been destroyed.

a Where are the alveoli? ..................................................................................

(1)b Explain why the cells in Pamir's body may not be getting enough oxygen.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

(2)Total marks: 25

Extension question

7 Sven did an experiment to compare the rate of respiration in woodlice andmaggots. This is the apparatus he used.

a Describe three things that Sven would need to keep the same in each tube.

1 .......................................................................................................................

2 .......................................................................................................................

3 .......................................................................................................................

(3)


A B C D

live woodlice

hydrogencarbonateindicator solution

gauze platform

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test tube


b Explain why it was a good idea to use two tubes with maggots and two with woodlice, rather than just one of each.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

(1)c Sven timed how long it took for the indicator to change from red to

yellow. Here are the results that Sven wrote down:

tube A 5 minutes 30 secondstube B 6 minutes 15 secondstube C 9 and a half minutestube D 8 minutes exactly

Draw a results table so that these results can be seen and understood clearly.

(3)d Calculate the average time that it took for the indicator in the ‘maggot’

tubes to change colour. Then do the same for the ‘woodlouse’ tubes.

maggot tubes .................................................................................................

woodlouse tubes ............................................................................................

(2)e What could Sven conclude from his experiment?

.........................................................................................................................

.........................................................................................................................

(1)Total marks for Extension: 10



Text answers

1 a Glucoseb The starch molecule must be broken down; it is digested; into individual

glucose molecules.2 a Glucose and oxygen

b Carbon dioxide and water3 a Both respiration and burning involve: combining with oxygen; producing

carbon dioxide and water; changing chemical potential energy in the glucose into other forms of energy.

b Respiration takes place much more gently than burning. Less heat energy is released.

4 a From the lungs to the heart, from the heart to a leg muscleb From the small intestine to the heart, from the heart to the lungs, from

the lungs to the heart, from the heart to a leg muscle5 Muscles need a lot of energy when they are working hard. They get this

energy from respiration, that is, from combining glucose with oxygen. Somuscles need a lot of glucose and oxygen. This is transported to them in theblood. The heart beats faster to move the blood faster, so that glucose andoxygen get taken to the muscles more quickly. (This also helps to removecarbon dioxide from the muscles more quickly.)

6 a The blood in veins is deoxygenated. It has been to the body cells where it gave up its oxygen, and is on its way back to the heart.

b As soon as a blood vessel is cut, the blood comes into contact with the oxygen in the air and is oxygenated.

7 a lowb high, respiringc blood, alveoli


1 a Respiration, vein, hydrogencarbonate indicator, alveoli, capillariesb Gas exchange: the diffusion of oxygen from the air into the blood, while

carbon dioxide diffuses from the blood into the airArtery: a blood vessel that carries blood away from the heartHeart: a muscular organ that pumps blood around the bodyLime water: a clear liquid that becomes milky when in contact with carbon dioxideOxygenated: containing oxygenDeoxygenated: containing only a very little oxygenEmphysema: an illness in which the tiny alveoli are damaged

2 a 1%b 4%c Oxygen is used by the body cells in respiration.

Worksheet answers

E1 Energy from icing sugar1 The lid should blow off the top of the tin.2 icing sugar/glucose; carbon dioxide3 From the air in the tin4 chemical potential; heat; sound

RespirationC

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ANSWERS


E6 Comparing the carbon dioxide content of inspired air and expired air1 The liquid will first change colour in tube B.2 Expired air3 Inspired air contains less carbon dioxide than expired air.


1 a Oxygen; water (2)b Hydrogencarbonate indicator or lime water (1)c If hydrogencarbonate indicator: red; yellow

If lime water: colourless/clear; milky (2)2 a One arrow O drawn from space inside the alveolus into the blood (1)

b One arrow C drawn from the blood to the space inside the alveolus (1)c Right (1)

3 a One mark for each correct label (3)b Shading in spaces inside the left side of the heart (not in the muscle

making up the heart wall)Shading inside the artery from the left side of the heartShading inside the vein to the left side of the heart (total 3)

4 a Combining/reacting (not ‘mixing’); oxygen with glucose; in a reaction called respiration (2)

b Respiration provides energy for muscles;the harder they work the more energy they need;respire more quickly (when working/running);so need more oxygen/glucose;faster heart beat makes blood move faster;delivering, oxygen/glucose, more quickly (max. 3)

5 a Every living cell respires. (1)b Expired air contains more carbon dioxide than inspired air. (1)c Glucose is combined with oxygen inside your cells. (1)

6 a Inside the lungs (1)b Fewer alveoli means less movement of oxygen/gas exchange; so less

oxygen in the blood (2)Total marks: 25

Extension answers

7 a Any three of: the mass of animals (not the ‘amount’ or ‘number’); the volume of indicator (not the ‘amount’); the concentration of the indicator; the size of the tube; the temperature; the material the platform is made of (max. 3)

b To avoid ‘odd’ results (1)c Correct and clear table drawn with ruled lines and headings; headings

contain units; headings state whether maggots or woodlice in tubes; readings converted to seconds (max. 3)

d Maggots 352.5 seconds; woodlice 525 seconds (2)e The maggots respired more rapidly than the woodlice. (1)




Chapter 5 Answers

Pupils should be familiar with the following ideas:• That sounds are produced by vibrating sources• How sounds produced by musical instruments can be changed

6 Sound and hearing

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AmplifiedAmplitude of vibration

AnvilAudible rangeAuditory nerveCathode ray oscilloscope

Cochlea

CompressionDecibel scaleEar canalEar drumElectrical impulsesFrequency of vibration

Hair cellsHammer

Hearing rangeHertz (Hz)High pitchInfrasoundLoudnessLow pitchNoiseOuter earRarefaction

Sound energySound waveStirrupSupersonicUltrasoundVacuumVibration

In this topic pupils should learn:• to explain how sound travels through media• to explain how the ear works• to find out about the harmful effects of loud noise and how loud noise can be

reduced• to decide on a suitable question to investigate and on what type of data to

collect• to identify relevant variables and to consider how to control or take account of

them• to evaluate data, considering alternative explanations• to investigate the loudness of sounds using an appropriate strategy

Learning checklist

Links

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Unit Title5F Changing Sounds


CH A P T E R

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6 Sound and hearing

ICT

Most pupils

Scientific enquiry• Identify patterns in qualitative data about sound and describe sound qualities• Frame a question about hearing which can be investigated• Identify and control key variables• Identify limitations in their data• Compare sound levels and report on a loudness enquiry• Describe a current issue related to soundPhysical processes• Relate changes in pitch and loudness of sounds to changes in vibrations• Explain how musical instruments can make these changes and relate these to

the oscilloscope representations of waves• Recognise that sound needs a medium to travel through and that it travels at

different speeds through different media• Explain simply how the ear works and give examples of hearing ranges• Describe ways in which hearing can be impaired and how noise pollution can

be reduced

Pupils who have not made so much progressScientific enquiry• Measure sound levels and describe a range of sounds• Describe what they found out from an investigation into hearing• Compare sound levels, and report on loudness of sound in common situationsPhysical processes• Relate sound to vibration and identify a range of sources or vibrations• Recognise that sound travels but cannot travel through a vacuum• Explain that sound waves cause our ear drums to vibrate and that this enables

us to hear• State that loud sounds can damage hearing

Pupils who have progressed furtherScientific enquiry• Select an appropriate approach to investigating a question about hearing• Present a reasoned argument about a current issue in the science of hearingPhysical processes• Relate pitch to frequency of sounds and loudness to amplitude• Use particle theory to explain how sound travels through materials• Use a model of the ear to discuss possible causes of hearing impairment

Learning outcomes


Cross-curricular linksMusic: unit 3 ‘Soundscapes’.

ICTUnit 7 ‘Measuring physical data’.

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Most pupils will already know that sounds are made as a result of vibrations. Thetopic is introduced and these ideas confirmed by considering lots of differentsources of sounds and asking the question ‘Why are these objects producingsounds?’ This can be quickly followed by other questions such as ‘How do youthink the sound would change if the bee flapped its wings faster/slower?’ Withoutconfirming or denying any predictions pupils can then carry out Worksheet F1,Producing sounds.

From these exercises, and particularly the metre rule experiment, pupils can seefor themselves that (a) sounds are produced by vibrating objects, (b) small objectsvibrate quickly and produce high pitch sounds and (c) large objects vibrate slowlyand produce low pitch sounds.

Frequency of soundsHaving established the relationship between the ‘rate of vibration’ of an objectand the pitch of the sound it produces we can introduce the idea of frequencyand its unit, hertz (Hz). If an object has a frequency of 100 Hz this means itvibrates 100 times each second and the frequency of the note it produces willalso be 100 Hz. Notes that have a high frequency also have a high pitch.

Pupils’ knowledge of sound can now be linked with different musical instruments.Music is a mixture or progression of musical sounds. How do musical instrumentsproduce these different sounds? There are photos of some musical instruments onpages 78 to 80 of the Pupil Book that can be used to tease out the key features.

Using a signal generator we can demonstrate the effect of making a loudspeakervibrate at different frequencies, producing high pitch and low pitch notes. It is anatural consequence of this experiment that pupils discover that there are soundswhose frequencies are so low or so high they cannot be heard. The range offrequencies pupils can hear is called their hearing range. This varies a little fromperson to person and usually narrows with age. Typical values for a hearing rangeare from 20 Hz to 20 000 Hz. Sounds with frequencies higher than this uppervalue are called ultrasounds. Using the block graph and other information onpages 81–82 of the Pupil Book we can point out that not all animals have thesame hearing range. Questions 4, 5, 6 and 7 provide opportunities for pupils toconfirm what they have learned.

LoudnessAnother property of a sound is its loudness. Using various music instruments orobjects, pupils can be asked how they can produce loud and soft sounds fromeach of them. This can then lead to the idea that the objects vibrate with largeamplitudes when producing loud sounds and with small amplitudes whenproducing quiet or soft sounds. The diagrams of drumskins and strings on page83 of the Pupil Book may help to give some visual reinforcement to the idea.

Seeing soundsNow is an appropriate point to introduce the cathode ray oscilloscope (CRO) asa piece of apparatus that shows on its screen a representation of a sound wave. Inthis way, the effect of altering the loudness and/or the frequency of a sound canbe seen. Using a signal generator and speaker pupils can hear a wide range ofsounds and see for themselves what a loud sound ‘looks like’. If time allows, amicrophone could be used so that pupils can ‘see’ their own voice.


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How does sound travel?Pupils can be given some idea of what a sound wave would really look like (if wecould see one) using a slinky. Sending longitudinal pulses along a long spring helpscreate the idea of moving compressions (places where particles are pushed closertogether than normal) and rarefactions (places where particles are more spreadout than normal).

Hearing soundsUsing a model of the ear or the picture on page 85 of the Pupil Book we can buildon the idea of the sound wave established above to explain how we hear sounds.The role played by each part of the ear should be understood by all pupils. Inorder to facilitate this, Worksheet F2, The ear, asks pupils to create a 2D model ofthe ear (cut and stick) and then to add labels that explain the functions of thedifferent parts. Once completed it becomes an effective tool in establishing howand why a person’s hearing may be impaired, e.g. perforated ear drum, excessivewax.

What kinds of materials can sound waves travel through?Pupils almost certainly already know that sounds can travel through solids, liquidsand gases, but they often do not realise that they know it. Examples such as• you can hear noises next door through the wall,• you can hear noises when you swim under water (for the non-swimmers the fact

that whales/dolphins can communicate with each other might be a betterexample), and lastly

• you can hear me when I speak,

should convince them of what they already know. Worksheet F3, What can soundstravel through?, provides fun activities for these facts to be confirmed and includesan experiment (the bell jar experiment) to establish that sound waves cannot travelthrough a vacuum as they need particles in order to pass through a medium.

Questions 12 and 13 on page 87 of the Pupil Book can be used to confirm apupil’s understanding of these ideas.

Speed of soundUsing some of the information on pages 87–88 of the Pupil Book pupils canconsider the idea that sounds travel through the air at about 340 m/s but theytravel at different speeds in different materials. As a general rule, the closer theparticles, the faster the speed of sound, so sounds travel quickest through solids,slightly slower through liquids and slowest of all through gases.

Worksheet F4, Planning to measure the speed of sound, is a paper exercise thatprovides an opportunity for pupils to design an experiment and demonstrate theirabilities to identify and control certain variables.

This section of work is finished by considering some everyday effects of the largedifference between the speed of sound and the speed of light, e.g. thunder andlightning, exploding fireworks. Using the information provided on page 88 of thePupil Book, question 14 can now be tackled by pupils.

Worksheet F5, Measuring the speed of sound using echoes, provides pupils with areal opportunity of measuring the speed of sound for themselves. Banging twopieces of sensibly sized wood together will usually create a sharp sound. The choiceof a suitable spot where an echo of the sound can be heard is the key to thesuccess of this experiment.

6 Sound and hearing


Noise pollutionThrough class discussion we can usually come to the conclusion that noise isunwanted sound. Pupils need to realise that it can cause stress, illness and evendeafness, so it is important that we monitor noise and control it. We measureloudness on a scale called the decibel scale. If a decibelmeter is available this canbe used to measure the loudness/noise level of different activities. If there is notone available there are typical values of various activities given on page 89 of thePupil Book that can be used. Worksheet F6, The decibel scale, then provides theopportunity for pupils to measure/estimate the loudness level of activities of theirown choice and to record these on a decibel graph.

Lastly, consideration needs to be given to ways in which noise pollution can beminimised. Several possible solutions are mentioned on page 89 of the PupilBook.

Questions 15 and 16 on page 89 of the Pupil Book can now be answered bypupils.

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The emphasis throughout the work on Worksheet F1, Producing sounds, is thatlarge objects vibrate slowly and produce low pitched notes and small objectsvibrate quickly and produce high pitched notes. The stringed musical instrumentsor sonometers should therefore be organised so that only the length of a stringcan be altered. This may mean taping in place the tension adjuster or otherstrings.

Providing wooden blocks or large corks on which pupils can strike their tuningforks will prevent possible damage to desk tops. To produce a loud, long-lastingnote from a tuning fork, give it a sharp rap on a piece of word or cork, notnecessarily a hard bang! If pupils find it hard to hear their tuning fork, placing thestem of the fork on a desk top while it is vibrating may make it easier to hear.

There is a definite knack to producing a sound from a straw. Only trial and errorwill lead you to the best way of doing this so try it for yourself before the lesson.Use only paper straws for this experiment; plastic ones are too stiff and will notwork. This experiment creates lots of litter, so have a large bin in the centre of thelab where all pieces of straw can be put at the end of the lesson. Pupils love thisexperiment. If you put out 500 straws, 500 straws will disappear! Keep hold ofall the straws throughout the lesson and only give each pupil a straw when theyneed one. Tell them that that is their one and only straw.

Signal generators come in all shapes and sizes. It is important that you arefamiliar with the one that you are going to use to demonstrate hearing range.Make sure that you know how to adjust the sounds and that they are loudenough for all the class to hear.

Pupils need to be close to this apparatus and approximately the same distancefrom the speaker. Once they have experienced sounds that are beyond theirhearing range and roughly what the limits are, they can play a game to find whohas the widest hearing range in the class. For example, tell them to close theireyes and put their hands up. When they can no longer hear a sound from thespeaker they put their hands down, etc.



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6 Sound and hearing

Seeing soundsWithout a doubt this is one of those lessons that pupils remember for a longtime, providing it goes right. The cathode ray oscilloscope (CRO) is a wonderfulpiece of apparatus that just occasionally has a mind of its own. Make sure youhave a really good understanding of how it works and how to obtain theappropriate picture of a wave on your scope. Sending for a lab technician oranother teacher because you cannot obtain a picture will greatly affect classenthusiasm. Lots of practice before the lesson will ensure lots of success in thelesson... There is no alternative!

When you have gained a high level of expertise you may want to try connectinga microphone to the CRO. One last word of advice: try it before the lesson. Makesure you know what adjustments you have to make to get it to work.

How does sound travel?Three words of advice when using the slinky: Don’t let go! It can cause greatamusement to a class but it can be highly frustrating spending half the lessonunravelling a knotted slinky. To avoid this try the following. Choose your mostreliable pupil! Give them one end of the slinky and keep hold of the other end.Stretch the slinky out on the floor, in the middle of the lab so all pupils can see it.Tell your chosen assistant that they are to keep hold of the end of the slinky at alltimes and not let go of it. First, send single pulses along the slinky. Then moreregular ones with even spaces between compressions. Compare your pushes ofthe spring with the pushes of the prongs of a tuning fork on the air particlesaround it. What you see in the slinky is a model of a sound wave. Diagramsshowing frozen views of a slinky are useful.

Hearing soundsWorksheet F2, The ear, is very straightforward but it is always a good idea toemphasise to all pupils that they should keep the glue away from all books. Ifthere is a model of the ear available in the department this could be on displayfor pupils to ‘come and look at some time during the lesson’. But not all at once!

What kinds of materials can sound waves travel through?The more examples that can be provided of sounds travelling through solids,liquids and gases the more relevance this topic has. How do your mum and dadknow if you are playing loud music in your bedroom if you have the door shut?Try to find some whale songs and let the class listen to them.

The string telephone is a good experiment that is enjoyed by most pupils butsometimes pupils do the experiment without thinking about what it isdemonstrating. Walking around and asking appropriate questions of groups suchas ‘How does the sound travel from your mouth to his ear?’ helps to get them tofocus on the important principles. Other questions that might be asked include:‘Does the phone work if the string is slack?’, ‘Can you speak to more than oneperson on your phone?’, ‘How loud is the sound you can hear?’

Speed of soundThe paper exercise on Worksheet F4, Planning to measure the speed of sound, canbe carried out as a whole class, small group or individual exercise. It is designednot only to show how we can determine a value for the speed of sound but alsoto encourage pupils to think about how they would carry out the experiment andhow and why they would need to control key variables. It also serves as a goodintroduction to the experiment described on Worksheet F5, Measuring the speedof sound using echoes, which pupils will carry out for themselves.


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Sc1

Scientific Enquiry

1b, 2a, 2b, 2e, 2h, 2i, 2k, 2p

Sc2


Sc3


Sc4

Physical Processes

2a, 3a, 3g, 3h, 3i,3j, 3k


It is important to wander around the school to discover the best place to carryout this experiment, bearing in mind not only the creation of a suitable echo butalso the potential disruption you may cause your colleagues. Make sure thatpupils are familiar with the stopwatches they are given, know how they workand can read them. It is a good idea to take a few spares with you just in case!Being able to hear the echo is obviously crucial to this experiment but somepupils will be unsure what they are listening for. Start the experiment by bangingthe pieces of wood together and listening as a whole group for the echo withoutworrying about the stopwatches. Once everyone is happy that they can hear theecho, the experiment proper can begin.

Working out the averages and the final speeds will require the use of calculators.

If time is available group results can be collected and a class value for the speedof sound found. This can then be compared with the accepted value.

Noise pollutionThe more relevant this topic can be made to the personal experiences of pupils,the better they will understand it. Discussions about noise from a nearby factory,local main roads, airports, etc. are likely to be useful. Questions and answersabout the possible long-term effects of attending lots of very loud pop concertsor playing personal stereos loudly will also help to tease out key issues.

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What I have learnt

Sound and hearing


Audible range

Cochlea

Sound wave

Ear canal

Anvil

Electrical impulses

Hertz (Hz)

Loudness

Vibration

Outer ear

Noise

Compression

Decibel scale

High pitch

Infrasound

Rarefaction

Low pitch

Sound energy

Hearing range

Ear drum

Hair cells

Supersonic

Ultrasound

Auditory nerve

Stirrup

Hammer

VacuumAmplified

Amplitude ofvibration

Frequency of vibration

Cathode ray oscilloscope

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• I know that sounds are made as aresult of vibrations

• I know that small objects vibratequickly and produce highfrequency or high pitch sound

• I know that large objects vibratemore slowly and produce lowfrequency or low pitch sounds

• I know that objects that vibratewith a large amplitude produceloud sounds

• I know that sound energy travelsas a wave

• I know that sound waves can travelthrough solids, liquids and gasesbut not through a vacuum

• I know that sound waves travel atdifferent speeds through differentmaterials

• I know that sound energy iscollected by the outer ear,amplified and transmitted throughthe inner ear to the auditory nerve

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Lesson Focus Pupil Book 2 pp. 78–79Sounds are made as a result of vibrations

Expectations

Most Pupils Will recognise that sounds are created by objects that are vibrating.Different sounds are created by objects vibrating differently.

Less Able Pupils Will recognise that sounds are created by objects that are vibrating.

More Able Pupils All the above and also recognise that smaller objects producesounds with higher pitches.



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Worksheet F1 Producing sounds

Circus of experimentsA String experiment.Three or four sonometers or stringedmusical instrumentsB Tuning fork experimentThree or four pairs of tuning forks, onelarge, one much shorterBowl of waterWooden blocks or large corksC Metre rule experimentThree or four metre rulesD Reed experimentSix to eight paper straws (per session)Three or four pairs of scissors

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10 In and register. More able pupils will know the answers to many Starter. Use the photographs/diagrams on pages 78–79 of the Pupil Book to of these questions from earlier work and be more begin a discussion about how sounds are created. Accept all ideas but do not precise in their choice of words. Less able pupils reveal which ideas are correct. Inform pupils that the circus of experiments they may need to be encouraged to give their answers.are going to carry out should help them decide whose ideas are correct.

35 Development. Worksheet F1 Producing sounds. Pupils are allocated one of Less able pupils may need some help in following Pupils see for themselves that objects that produce sounds are the four experiments. After 6–7 minutes they are told to move on to the next the instructions on Worksheet F1. vibrating.experiment. Pupils jot down as they go the answers to the questions on the worksheet.

5 Plenary. Quick Q and A session with the whole class to confirm their More able pupils will already have realised the Pupils may now realise that objects may produce different observations and conclusions. To lay the foundations for the next lesson, pupils relationship between frequency of vibration and sounds by vibrating in different ways.are asked why vibrating objects produce different sounds. the pitch of the note produced.

Homework: Pupils write a summary of what they have discovered together with examples of objects that are vibrating and producing sounds.


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Lesson Focus Pupil Book 2 pp. 79–82Relate changes in pitch of sounds to changes in frequency of vibrationHearing range and ultrasound

ExpectationsMost Pupils Know how the size of an object can determine the frequency at

which it vibrates and the sounds it produces. Know that we have ahearing range that varies from person to person. Some animalshave different hearing ranges from that of humans.

Less Able Pupils Know that large objects vibrate slowly and produce low pitchednotes, and small objects vibrate quickly and produced higherpitched notes. There are some frequencies of sound we cannothear but some animals can.

More Able Pupils All the above and know the hearing range for a human isapproximately 20 Hz to 20 000 Hz. Sounds which havefrequencies so high that we cannot hear them are calledultrasounds.



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Demo: Hearing rangeSignal generatorConnecting cablesSpeaker

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10 In and register. More able pupils will remember more examples Large objects vibrate slowly and produce low pitch notes. Starter. Through a whole-class Q and A session remind pupils that all sounds to support this outcome. Small objects vibrate more rapidly and produce higher pitched begin with an object that is vibrating. Tease out of them using what they notes.observed when they did their circus of experiments the differences in the sounds produced by the two tuning forks, the two strings, etc. Confirmation of their conclusions and more examples of sources of sounds are found on pages 79–80 of the Pupil Book.

15 Development. With this extra support available pupils describe how high and Less able pupils may need some support in low pitched notes are produced using examples of their own choice. Pupils may accurately expressing their ideas on paper.then answer questions 2 and 3 on page 79 of the Pupil Book. This is an ideal place to discuss briefly how musical instruments produce notes of different pitches. Some examples are illustrated on pages 78–80 of the Pupil Book.

5 Introduce the idea of measuring the frequencies of sounds in hertz (Hz). The frequency of a sound is measured in hertz (Hz).

15 With pupils seated around the front of the laboratory, you can introduce a There are sounds that have frequencies we cannot hear. The signal generator (a piece of apparatus that can produces sounds with a wide range of frequencies we can hear is called our hearing range range of frequencies/pitch). Vary the frequency of the sound. Can you hear the or audible range. Different people will have slightly different sound? Vary the frequency again. Can you hear the sound? Continue with this hearing ranges. Sounds with too high a frequency for us to until all pupils realise that there are sounds they cannot hear because the hear are called ultrasounds.frequencies are either too high or too low.

5 Plenary. Some animals are able to hear sounds we cannot, e.g. dogs can hear Less able pupils may need some help in Different animals may have different hearing ranges from that dog whistles. Discuss the block graph of hearing ranges of different animals on interpreting the information on the block graph. of human beings.page 82 of the Pupil Book.

Homework: Questions 5, 6 and 7 on pages 81 and 82 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 82–83Loudness of soundsOscilloscope representations of sounds

ExpectationsMost Pupils Know how changes in amplitude of vibration will affect the

loudness of the note produced. Will recognise how therepresentation of a sound wave on a CRO changes as we alter thefrequency and/or the loudness of a sound.

Less Able Pupils Know that large vibrations produce loud sounds and smallvibrations produce quiet sounds. Know we can createrepresentations of sound waves.




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Demo: CROSignal generatorWiresSpeakerCathode ray oscilloscope (CRO)Optional: microphone

Musical instruments

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10 In and register.Starter. Class discussion. How do we make an object produce a loud/quiet sound? Discuss several examples, e.g. tuning folks, strings, drums. Ask pupils how the vibration of an object producing a loud sound is different from one creating a quiet sound.

10 Development. Using the explanations and the diagram on pages 82–83 of the Less able pupils may have more difficulties When an object vibrates with a large amplitude it produces a Pupil Book introduce pupils to the idea of amplitude of vibration. Under the choosing the correct words and phrases to describe louder sound than when it vibrates with a smaller amplitude. heading ‘Loudness’ pupils explain briefly, including diagrams, how a vibrating how an object is vibrating.object can produce (a) a loud sound and (b) a quieter sound. More able pupils will use a more appropriate

vocabulary.

20 Pupils gather around the front of the laboratory and are reminded that a signal More able pupils may be able to predict how the Pupils are able to recognise the main features of a sound wave generator is a piece of apparatus that can be used to produce lots of different wave representation is going to change as the represented on a CRO.sounds. The loudspeaker allows us to listen to the sounds. The new piece of sound produced by the signal generator is altered.apparatus is called a cathode ray oscilloscope and creates representations of the sound waves they are hearing. Pupils are then shown the representations of lots of different sounds. Tease out the features that change on the CRO when the sounds are louder, quieter, higher pitch, lower pitch, etc.

10 Plenary. Under the heading ‘Seeing sounds’, pupils draw CRO diagrams for lots of different types of waves with a description of each beneath.

Homework: Finish any incomplete diagrams, then do questions 8 and 9 on page 83 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 84–85Model of a sound wave using a slinkyHow the ear works

Expectations

Most Pupils Can explain simply how the ear works and can describe ways inwhich hearing might be impaired.

Less Able Pupils Know that sound waves cause our ear drums to vibrate so that wecan then hear sounds.

More Able Pupils All the above but can explain the workings of the ear moreaccurately and in more detail.



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Demo: Sound wavesSlinky

Worksheet F2 The earPer pupil: scissors and glue

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20 In and register. Less able pupils may have difficulties with words Pupils recognise that some of the features of a sound wave Starter. Remind pupils that sounds start with a vibrating source and then travel such as compressions and rarefactions. can be shown using a slinky.outwards from the source as waves. This is then demonstrated to the pupils using Pupils can visualise how a sound wave moves through the air.a slinky. Confirmation of what they see, i.e. travelling compressions and rarefactions, and how this is related to sound waves can be achieved using the diagrams and explanations on page 84 of the Pupil Book.

25 Development. Using the diagram on page 85 of the Pupil Book or a model of Less able pupils may need some help with the Pupils know the main parts of the ear and their functions.the ear if one is available, ‘How the ear works’ is explained to the pupils. labels for the diagram.Using Worksheet F2 The ear and the Pupil Book, pupils confirm their understanding and make their own notes.

5 Plenary. Discuss with pupils why someone might have defective hearing, More able pupils may provide more examples of Pupils know some of the problems that may cause poor e.g. burst eardrum, build-up of wax. ear defects and have a better understanding of hearing or deafness.

how and why they affect hearing.

Homework: Questions 10 and 11 on page 85 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 85–87What can sound waves travel through?The particle theory of the movement of sounds

Expectations

Most Pupils Recognise that sounds need a medium to travel through.

Less Able Pupils Sound waves cannot travel through a vacuum but can travelthrough solids, liquids and gases.

More Able Pupils All the above and can use particle theory to explain how soundwaves travel through materials.



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Demo: Wave modelSlinky

Worksheet F3 What can sounds travelthrough?Experiments A and CPer group:Two plastic/paper cups2–4 m of string Matchstick or piece of splintExperiment DDemo: Bell jar experimentBell jarBellVacuum pumpPower supply for electric bell

Optional: whale songs

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10 In and register. More able pupils will be able to provide a more Starter. Remind pupils of how sound waves travel through the air (perhaps with accurate description of how sound waves can be the aid of the slinky again). represented in a slinky.

20 Development. Can sound waves travel through other materials apart from air? Less able pupils may need some help in drawing Pupils know that sounds can travel through solids and gases.Pupils can discover some of the answers carrying out Worksheet F3 What can conclusions from their observations.sounds travel through? Parts A and C can be done by the whole class in small groups. Part B is to be done as homework and part D is a demonstration experiment. Pupils do parts A and C now. Discussions with pupils as they do the experiment will help translate their observations into confirmation that sounds can travel through solids and/or gases.

15 Pupils sit around the front of the laboratory but with the safety screen between More able pupils will be able to describe in detail Sound waves cannot travel through a vacuum.them and the bell jar. The bell in the bell jar is turned on and pupils asked to why sound is unable to travel across a vacuum.make their observations: ‘Can you hear the bell ringing?’, ‘How is the sound More able pupils may be aware that light waves reaching your ear?’, etc. The vacuum pump is turned on. It is explained to the can travel across a vacuum.pupils that all the air is being removed from the bell jar. The questions are then repeated and explanations for any difference asked for. The experiment should be repeated several times.

5 Plenary. Draw together the conclusions from the three experiments, i.e. sounds More able pupils may be able to predict what will can travel through solids and gases but not through a vacuum. Can you predict happen in investigation B and explain why.what will happen in a liquid? Remind pupils what investigation B requires of them.

Homework: Carry out investigation B.


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Lesson Focus Pupil Book 2 pp. 87–88Calculating the speed of soundSpeed of sound in different materialsComparison of the speed of sound and the speed of light

ExpectationsMost Pupils Recognise that sounds travel at different speeds in different media.

Can describe in reasonable detail an experiment to find the speedof sound in air. Know that light waves travel much faster thansound waves.

Less Able Pupils Know that sounds travel and can take a considerable time to arrive.Know that the speed of sound in air can be found by experiment.Know that light waves travel faster than sound waves.

More Able Pupils All the above and can accurately describe an experiment to findthe speed of sound in air, demonstrating full control of keyvariables. Can explain accurately examples where there is a delaybetween seeing and hearing an event.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Pupils are asked to write a clear set of instructions for two pupils to follow in order to discover the speed of sound.Numeracy:ICT:


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Worksheet F4 Planning to measurethe speed of sound

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10 In and register. More able pupils will recognise the need for Pupils know that sound waves can travel through solids, Starter. Following on from the last lesson and the homework pupils should be particles to be present if a sound wave is to pass liquids and gases but not through a vacuum.able to confirm that sound can travel through solids, liquids and gases but through a material.not through a vacuum.

25 Development. Using the information on pages 87 and 88 of the Pupil Book Less able pupils may need some support in Pupils can devise a suitable approach to the experiment, pupils can now consider the idea of what the speed of sound is. A numerical thinking through the problem and putting their identifying and controlling key variables.value of 340 m/s and an illustration of what this means, e.g. from here to the ideas on paper.traffic lights at the end of the road in 1 s, is useful. The question of how this More able pupils should be able to write a clear value was arrived at can then be addressed using Worksheet F4 Planning to set of instructions and demonstrate an measure the speed of sound. The worksheet can be tackled as a whole class, understanding of controlling variables.small group or individual exercise.

10 Using the Pupil Book pupils can then be introduced to the idea that sound More able pupils will relate the speeds of sound Sound waves travel at different speeds in different materials.travels at different speeds in different materials. In general it travels fastest in waves in different materials to the arrangement solids and slowest in gases. Some values are provided. Some pupils may provide of the particles within the materials.an explanation of this in terms of how close the particles are in different materials and how this affects the speed of sound through that material.

5 Plenary. Pupils use some of their own experiences to compare the speed of More able pupils may offer more examples of the Pupils appreciate that light travels much faster than sound.light with the speed of sound, e.g. exploding fireworks, thunder and lightning. delay in the arrival of sound waves compared Again information and examples are given in the Pupil Book on page 88. with light waves.

Homework: Question 14 on page 88 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 87–88To determine the speed of sound in air

Expectations

Most Pupils Will be able to calculate a value for the speed of sound from theirmeasurements.

Less Able Pupils Will be able with some help to calculate a value for the speed ofsound.

More Able Pupils All the above and will understand the need to take severalreadings to improve accuracy. Will be able to make somecomments about the accuracy of their value and perhaps how theexperiment could be improved.



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Worksheet F5 Measuring the speed ofsound using echoesPer group:Two pieces of woodStopwatchMetre rule

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15 In and register. Pupils understand how the speed of sound can be calculated Starter. Give out Worksheet F5 Measuring the speed of sound using echoes. using echoes.Work through the sheet step by step explaining precisely what pupils should do and why. Inform all pupils what they need to take with them, e.g. pen, paper, stopwatch and two pieces of wood, where they are going to do the experiment and what route they are to take to get there.

25 Development. When all the class has arrived demonstrate how the two pieces Some pupils may need help in using a stopwatch of wood should be banged together to produce a loud sharp sound. Do this accurately.several times until pupils not only understand what is required but can also hear their echo. Give each of the groups a number and tell them that they are only to bang their pieces of wood together when you shout their number (otherwise it will be impossible to recognise your own echo). Alternatively, take just two pieces of wood and be the source of sound for all groups. (Bang the two pieces of wood together once every 5 seconds or so for 5–10 minutes.) When all groups have at least five readings, one person from each group should pace out the distance between the position where the pieces of wood were banged together and the reflecting wall or building. Return to the lab.

5 Using a metre rule measure the length of one pace for the person in the group Less able pupils may need help in calculating the who counted the number of steps it was to the wall/building. Work out the distance between the building/wall and where distance to the wall/building in metres. they were standing.

5 Plenary. Calculate an average for the time of the echo. Then calculate the speed Less able pupils may need help in calculating Pupils have their own calculated value for the speed of sound.of sound using the formula given. averages and the speed of sound using their

figures, and in understanding the units used.

Homework: Questions 1, 2 and 3 on page 92 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 88–89Noise, loudness of sounds and the decibel scale

ExpectationsMost Pupils Can give examples of sound levels on the decibel scale. Understand

the problems created by noise pollution and suggest ways ofreducing it and its effects.

Less Able Pupils Know that loud sounds can damage their hearing.

More Able Pupils All the above and can present a coherent argument about theeffects of noise on our well-being.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Plotting the noise levels of various activities on a decibel scale.ICT:


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Demo: Measuring sound levelsDecibelmeter

Worksheet F6 The decibel scale

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10 In and register. More able pupils will have a wider understanding Pupils understand why there is a need to monitor noise.Starter. A class discussion of what is meant by the word ‘noise’ should of the word ‘noise’ and be more aware of some eventually lead to the idea that it is unwanted sounds. A second question, of its effects.‘What are the possible effects of sound on us?’, should lead to ideas of stress, loss of concentration and, at its more extreme, illness including deafness. To monitor situations we measure noise levels using a decibelmeter.

30 Development. If a decibelmeter is available the whole class could measure More able pupils will be able to predict more Pupils understand how loudness levels are expressed on the noise levels such as someone whispering, talking normally and shouting. Levels accurately the decibel levels of different activities. decibel scale.from radios, machinery, etc. could also be included where possible. These values could then be compared with those on page 89 of the Pupil Book.Give out Worksheet F6 The decibel scale. Using their own measured values, plus some from the Pupil Book, plus some they have estimated for themselves, pupils draw other diagrams on the Worksheet. If no meter is available then begin with a discussion about the values of sound levels described on page 89 of the Pupil Book.

10 Plenary. The lesson can be finished by discussing ways to avoid ‘noise pollution’ Pupils understand how the effects of noise pollution can be as mentioned on page 89 of the Pupil Book. reduced.

Homework: Questions 15 and 16 on page 89 of the Pupil Book. Revise for End of Unit test.


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ExpectationsMost Pupils Demonstrate secure knowledge and understanding of sound and

hearing.

Less Able Pupils Demonstrate some knowledge and understanding of sound andhearing.

More Able Pupils All the above, plus the knowledge and understanding to interpretexperimental results.



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Worksheet F7 Sound wordsearch


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10 In and register. Pupils will be better prepared for test.Starter. Pupils can do last minute revision from the Pupil Book or have a go at the wordsearch.

30 Development. Seat pupils for test. Give out test. Issue relevant instructions More able pupils will answer more questions Pupils will consolidate knowledge gained by completing the about behaviour. Pupils do test. correctly and will attempt the extension question. End of Unit test.

10 Plenary. Pupils can finish wordsearch or do end of chapter questions.

Homework:


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UN I T

A String experiment

1 Move the bridge so the string has one short part and one long part. Pluckthe shorter string.

2 Watch what the string does and listen to the sound it produces.3 Pluck the longer string.4 Watch what the string does and listen to the sound it produces.5 What is producing each of the notes?6 Why do the notes sound different?

B Tuning fork experiment

1 Strike the large tuning fork on a hard object.2 Place the end of one of the prongs so that it is just touching the surface of

some water.3 What is produced on the surface of the water? What does this prove?4 Strike the tuning fork on a hard surface again and listen to the sound it

produces.5 Repeat steps 1–4 with a smaller tuning fork.6 What is producing the sounds you can hear?7 Why do the notes sound different?

F1 Producing sounds (page 1)

CHAPTER

WORKSHEET1

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➤continued

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sonometer

wooden sounding box

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F1 Producing sounds (page 2)

CHAPTER

WORKSHEET1

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C Metre rule experiment

1 Place a metre rule over the edge of a desk as shown in the diagram above.2 With the part of the rule on the desk held tightly in place, twang the rule.3 What do you see happening to the rule? What can you hear?4 Now alter the length of the rule hanging over the edge of the desk and

repeat step 2.Why does the rule produce different sounds?

D Reed experiment

1 Cut the end of a drinking straw so that it has the shape shown in thediagram above.

2 Squash this end of the straw slightly and then place it in your mouth sothat this shaped piece is a few centimetres inside your mouth and is nottouching your lips.

3 Blow gently. As you blow, slowly pull the straw as though you are pullingit out of your mouth. Before you pull the straw completely from yourmouth you should hear a sound.

4 What is producing the sound?5 Repeat steps 1–3 with a shorter straw.6 Why does the shorter straw produce a different sound?

SummaryWrite a short summary of three or four sentences describing what you havediscovered from these experiments.


The main parts of the human ear are shown below.

1 Cut out each of the parts and glue them onto a piece of A4 plain paper toshow the structure of the human ear.

2 Label each of the parts of the ear.3 Add to each label a short description of what that part of the ear does.

UN I T

F2 The earCHAPTER

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F3 What can sounds travel

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A Solids1 Put a small hole in the bottom of two paper/plastic drinking cups.2 Place the cups base to base, and thread a piece of string 2–4 m long

through each of the holes.

3 Tie a small piece of a wooden splint or a matchstick to each of the ends sothat when the string is pulled taut the wood prevents the string from beingpulled back through the holes.

4 Pull the string taut and ask your partner to whisper into one of the cupswhile you hold the other cup to your ear.

5 What can you hear? What does this prove?6 How can three people who are using string telephones listen to one person

whispering?7 Place your ear on the surface of a desk.8 Ask a friend to gently tap the desk about 1–2 m from your ear.9 What happens? What does this prove?

B LiquidsExperiment to be done as homework!

1 Lie in your bath with both of your ears out of the water.2 Tap the side or end of the bath with your toe 6–10 times.3 As you are doing this tilt your head so that one of your ears goes under the

surface of the water.4 What happens? What does this prove?

C GasesLook around the room you are in. Your friends will be carrying out some ofthe experiments on this sheet. As they do so you can hear them movingaround and talking. Write down a sentence or two to explain how are youable to hear them. ➤continued

D A vacuumThe diagram below shows the apparatus your teacher will use to discover ifsounds can travel through a vacuum.

Write a few sentences describing how you think your teacher will use theapparatus.

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ringing bell

to vacuum pump

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Katy and Richard want to carry out an experiment to discover the speed ofsound. In order not to disturb anyone, they have taken all their apparatusinto a quiet but hilly part of the countryside. Their apparatus consists of avery long measuring tape, a stopwatch and a cannon.

Katy and Richard know that:

a To find the speed of sound they need to measure how far it has travelled and how long it took to travel that distance. Then they can use the equation

Speed (m/s) = distance travelled by sound (m)time taken (s)

b When a cannon is fired it produces a large cloud of smoke and a loud sound at the same time.

c Sound waves travel much slower than light waves.

Katy and Richard carried out their experiment several times on differentdays. They discovered that the speeds that they calculated seem to vary fromday to day.

F4 Planning to measure the

speed of sound

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1 What instructions should Katy and Richard follow in order todiscover the speed of sound? Explain what measurementsthey should take and how they should make them.

Qu

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2 Why did the values they calculated vary from day to day? Giveone reason.

3 How could Katy and Richard modify their experiment in orderto overcome this problem?

4 Find out how the speed of sound in water was first measured.Qu

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When a sound wave strikes a hard surface it is reflected. This reflected waveis called an echo. We can use echoes to find the speed of sound.

1 Stand at least 150 m from a reflecting surface such as a tall building, wall or hill.

2 Bang two pieces of wood together to produce a loud sharp sound.3 Listen carefully: you should be able to hear an echo of the sound.4 Repeat step 3 several times until you are sure you can hear the echo

clearly.5 Bang the two pieces of wood together. At the same time your partner

should start a stopwatch.6 When your partner hears the echo he or she should stop the stopwatch.

The time shown tells you how long it took the sound to travel from you to the reflecting surface and back again. Note down this time.

7 Repeat steps 5 and 6 at least four more times. Then take an average of your results.

8 Pace out the distance between where you are standing and the reflecting surface that is creating the echo. Note down your result.

9 Using a metre rule measure your pace. Note this down too.10 Work out the distance to the reflecting surface using the equation

Distance to reflecting surface = number of paces x length of each pace

11 The sound waves you created travelled out and back, so the total distance travelled = 2 x distance to the reflecting surface.

12 Calculate the speed of sound in m/s using the equation

Speed (m/s) = distance travelled by sound (m)time taken (s)

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F5 Measuring the speed of

sound using echoes6

CHAPTER

WORKSHEET5


at least 150 m

Drawn below is a labelled axis for the decibel scale. Draw diagrams showingactivities that produce sounds. The diagrams should be drawn in positionsthat indicate the decibel level of the sounds produced. The first one hasbeen done for you. A jet aircraft taking off will produce sounds ofapproximately 100 dB.

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F6 The decibel scaleCHAPTER

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dB

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There are 20 words associated with sound hidden in this wordsearch. Howmany can you find?

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F7 Sound wordsearchCHAPTER

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H A M M E R L A N A CC U B O H S O U N D AT A L W E E D R A R PI I X T A I S S A L LP V E A R W E T N I OV D U X I A B G H C HI F Q U N V S J H G CB L K C G E N O I S ER O A M P L I T U D EA U D I B L E L W N UT D E Q R M P V U R DI D R U M O K N R C XO Y P I D E C I B E LN S T E T S I O P Z NH E R T Z E L I V N A


1 The diagram below shows a bee. As it flies we can hear a buzzing sound.

a What is making this buzzing sound?

..............................................................................................................................

(1)

b How is the sound being produced?

..............................................................................................................................

(1)

c How could the bee produce a higher pitched sound?

..............................................................................................................................

(1)

2 The string on a guitar vibrates 100 times in 2 s. What is the frequency ofvibration of the string?

..............................................................................................................................

(2)

3 Two musicians are playing in a band. One musician is playing a trombone andthe other is playing a harp.

a What does the trombone player do to produce low pitch notes from her instrument?

..............................................................................................................................

(1)b How does the harp player produce high pitch notes from his instrument?

..............................................................................................................................

(1)

End of Unit test

Sound and hearing

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6

239

4 Bill has a hearing range of 20 Hz to 20 000 Hz.

a Explain in your own words what this statement means.

..............................................................................................................................

..............................................................................................................................

(2)b What are ultrasounds?

..............................................................................................................................

(1)c Name one animal that can hear ultrasound.

..............................................................................................................................

(1)5 In the space below draw

a a string fixed at both ends which is vibrating with a large amplitude.

(1)b a string fixed at both ends which is vibrating with a small amplitude.

(1)

c What kind of sound will the string in part a produce compared with the string in part b?

..............................................................................................................................

(1)




6 The diagrams below show four wave patterns on an oscilloscope. Each ofthe patterns has been produced by a sound.

a Which pattern shows the loudest sound?

..............................................................................................................................

(1)b Which pattern shows the sound with the highest frequency?

..............................................................................................................................

(1)

7 Why is there often a delay between seeing a firework explode in the skyand hearing the sound of the explosion?

..............................................................................................................................

..............................................................................................................................

(1)

8 A noisy factory is built on the far side of a field opposite some houses.

a What effect might the noise in the factory have on its workers?

..............................................................................................................................

(1)b Suggest one way in which the workers could avoid this problem.

..............................................................................................................................

(1)c Suggest two ways in which the amount of noise reaching the homes from

the factory could be reduced.

..............................................................................................................................

..............................................................................................................................

(2)

A

C D

B



9 When there is airinside this jar the bellcan be seen andheard as it rings. When all the air hasbeen pumped out thebell can still be seento be ringing but itcannot be heard.

a What does this experiment prove about sound waves?

.........................................................................................................................

(1)b What does this experiment prove about light waves?

.........................................................................................................................

(1)

10 a Explain why sound waves travel more quickly in solids than they do in gases.

.........................................................................................................................

.........................................................................................................................

(1)b Explain the meaning of the word supersonic.

.........................................................................................................................

.........................................................................................................................

(1)

Total marks: 25

Extension question

11 A man standing 495 m from a wall claps his hands together. Three seconds later he hears the echo of his sound. Calculate the speed of sound. To get full marks you must show all your working out.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

(3)


ringing bell

to vacuum pump



Text answers1 Objects can produce sounds when they vibrate. We therefore have to

make an object vibrate if we want it to produce a sound.2 Any four small objects or musical instruments, e.g. bees’ wings, strings of

a violin, small triangle, short air column in a recorder. Small objects vibrate quickly and so produce high pitch notes.

3 Any four large objects or musical instruments, e.g. large tuning fork, long strings of a double bass or cello, large drum, long air column in an oboe. Large objects vibrate slowly and produce low pitch notes.

4 Pull the slide back so that the length of the air column is shorter. Shorter/smaller things vibrate more quickly and so produce higher pitched notes.

5 a 20 Hzb 20 000 Hz.

6 This is the range of frequencies of sounds you can hear.7 200 kHz.8

9

10 We make the outer ear larger and so can collect more sound.11 The sound waves will find it more difficult to reach the ear drum.12 Sound waves need particles in order to move. There are no particles in a

vacuum, so sound waves cannot travel through a vacuum.13 Yes. Even when all the air was removed from the bell jar we could still see

the bell ringing, i.e. the light waves could still travel through the bell jar.14 a 2 km

b 5 kmc 7 km

15 Stress, lack of concentration, permanent damage to hearing, headaches, sickness, etc.

16 Wearing ear protectors, installing double glazing, erecting a barrier between source of noise and people, turn the music/TV down.

Sound and hearingC

HAPTER

6

ANSWERS


Literacy activity answersa The pitch of the siren suddenly dropsb The Doppler effectc Occurrence, happening, eventd The speed of the vehiclee The stars, the heavens, the universef Radar, measuring the speed of different galaxies, navigation (by bats)g Because it is blind and therefore cannot use light wavesh Bats use ultrasounds to help them navigate and catch their prey

End of chapter answers1 a Decibel scale: used to measure the loudness of sounds

b Frequency: the rate at which an object is vibratingc Noise: unwanted soundsd Vacuum: a space that contains no particlese Ultrasounds: sounds that have frequencies that are beyond our audible

rangef Hearing range: spread of frequencies that can be heard by human beingsg Amplitude: how far an object moves from its resting place as it vibrates

2

c The note produced by the string in a will be louder that that produced by the string in b.

3 a Violin, piccolo, triangle, etc. – any three small musical instrumentsb Double bass, euphonium, kettle drum, etc. – any three large musical

instrumentsc Piano, harp, xylophone, etc.d Inside the piano there are long and short strings. When the long strings

are made to vibrate, low pitch notes are produced. When the short strings are made to vibrate they produce notes with much higher pitch.

4

5 a There is no atmosphere on the Moon and therefore no particles to carry sound from one astronaut to the other.

b When the astronauts touch helmets the sound waves are able to pass from one solid helmet to the other so the astronauts can hear each other.

6 Answers will vary

Chapter 6 Answers

ab

a b


7 A Outer ear: part of the ear that reflects sound waves into the earB Ear canal: channel along which sound waves enter the earC Ear drum: skin/membrane that is made to vibrate by sound wavesD Three bones – hammer, anvil and stirrup: change small vibrations into

much bigger vibrationsE Hair cells: they produce small electrical impulses when stimulated by

vibrationsF Auditory nerve: electrical impulses pass along this to the brain

Worksheet answersF1 Producing sounds

String experiment: the notes are produced by the vibration of the strings; thenotes sound different because the shorter string is vibrating faster than thelonger string.

Tuning fork experiment: the vibrating tuning fork produces the sounds; thenotes sound different because the shorter tuning fork is vibrating faster thanthe larger one.

Metre rule experiment: the rule is vibrating so you can hear a sound; the ruleproduces different sounds because it is vibrating faster or slower than before.

Reed experiment: the end of the straw (reed) vibrates, making the air in thestraw vibrate; in a shorter straw the length of the air column is smaller and soa higher pitched note is produced.

F3 What can sounds travel through?SolidsStep 5 You can hear the words of your partner. Sound can travel through a

solid (the string).Step 6 Cross the strings of two telephones.Step 9 You can hear the tapping through the desk. Sound can travel through a

solid (the desk).

GasesTheir vibrating larynxes (voice boxes) create sound waves (travelling vibratingair particles), some of which are gathered by our outer ears.

F4 Planning to measure the speed of sound2 The value calculated could vary because of wind. The sound will travel faster

with the wind and slower against it.3 They carry out the experiment in the usual way and calculate the speed of

sound. They then change positions so that the sound from the cannon istravelling in the opposite direction. They repeat the experiment, calculate asecond value for the speed of sound and then take an average for the tworesults. This value should be the true speed of sound.

F7 Sound wordsearchHammer, hertz, anvil, decibel, canal, ear, amplitude, audible, drum, vibration,pitch, wave, noise, loud, quiet, hearing, nerve, sound, ultrasound, echo

Chapter 6 Answers

245

End of Unit test answers1 a The bee’s wings (1)

b The wings are vibrating (1)c By vibrating its wings faster (1)

2 50 (1) Hz (1)3 a Makes the trombone long (1)

b Plucks the very short strings (1)4 a Bill can hear sounds that have frequencies between 20 Hz and

20 000 Hz (2)b Sounds that have frequencies that are so high we cannot hear them (1)c Any one of dog, cat, dolphin, bat, etc. (1)

5 (2)

c The string in part a will produce a louder sound than the string inpart b (1)

6 a A (1)b D (1)

7 Sound waves travel much more slowly than light waves (1)8 a Any one of stress, loss of concentration, damage to hearing (1)

b Wear ear defenders (1)c Build a barrier between the houses and the factory, e.g. a wall or plant

some trees (1) and install double glazing (1)9 a Sound waves cannot travel through a vacuum (1) or sound waves need

particles to travel (1)b Light waves can travel through a vacuum (1)

10 a The particles in a solid are much closer together than the particles in a gas (1)

b Faster than sound, i.e. a supersonic plane travels faster than the speed of sound (1)

Total marks: 25

Extension answer11 Speed = distance/time = 2 x 495/3 (1) = 330 (1) m/s (1)Total marks for Extension: 3

Suggested levels for marks gained0–9 working towards level 410–18 working towards level 519+ working towards level 6


Chapter 6 Answers

ab

Pupils should be familiar with the following ideas:• That micro-organisms are living organisms• The characteristics of micro-organisms and know that they feed, grow and

reproduce like other organisms• That organisms respire and produce carbon dioxide during the process• The names of some diseases caused by micro-organisms

7 Microbes and disease

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Starting points


AntibioticAntibodiesBacteriaBacteriumBarrierBreadCheese

CholeraCiliaFungusImmunityInfectious diseaseLactic acidMicro-organism

MicrobeMucusPathogenPenicillinPolioSkinTransmission

VaccinationVirusWhite blood cellsYeastYoghurt

In this topic pupils should learn:• the features of viruses, bacteria and yeast• that micro-organisms share the characteristics of other living things• how to grow bacteria and fungi on agar jelly• how growing micro-organisms can make products, e.g. yeast is used to make

bread and bacteria are used to make yoghurt• about the role of micro-organisms in infectious diseases• how to design an experiment to compare rates of respiration• that pathogens are micro-organisms that can cause disease, and to give some

examples of diseases caused by pathogens• about the body’s defence systems and how immunisation can protect against

microbial infections• how infectious diseases are transmitted, and how ideas about the transmission

of infectious diseases have changed and are continuing to develop• how vaccination works• what antibiotics are

Learning checklist

Links

8HRS

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A C H E R N OT

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Unit Title6B Micro-organisms


CH A P T E R

7

T I M I N G

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Citizenship and PSHE: Links can be made in dealing with medical advances, thedevelopment of drugs and food safety.

Design and technology: Unit 9E(i) ‘Ensuring quality production (food)’.

History: Unit 20 ‘Twentieth-century medicine’ and Unit 21 ‘Scientific discoveries’in the history scheme of work.

LiteracyThere is a literacy activity on Alexander Fleming and penicillin in the Pupil Book.

NumeracyExtracting numerical data from a map; extracting data from a graph.


?b

ca

=8

2+

Most pupils

Scientific enquiry• Describe how understanding of how some infectious diseases are transmitted

has developed as knowledge about micro-organisms has increased• Point out trends and patterns in first-hand and secondary data• Draw conclusions from data and relate them to scientific knowledge and

understandingLife processes and living things• Classify bacteria, fungi and viruses as micro-organisms, name some of the

diseases they can cause and describe how they can be transmitted• Describe some of the defences the body has against disease and describe

immunisation as a way of improving immunity• Recognise that antibiotics are effective against bacteria but not against viruses

Pupils who have not made so much progressScientific enquiry• Describe how some infectious diseases are transmitted• Point out some patterns in data and use these to draw conclusionsLife processes and living things• Name some infectious diseases and describe how they can be transmitted• Describe immunisation as a way of protecting against infectious disease

Pupils who have progressed furtherScientific enquiry• Describe how scientists’ interpretation of evidence has led to new ideas about

the transmission of disease and to new drugsLife processes and living things• Explain how immunisation can improve immunity and describe how antibiotics

may be effective across a wide spectrum or against specific bacteria

Learning outcomes



Unit Title Unit Title7A Cells 8B Respiration7E Acids and Alkalis 9B Fit and healthy

248


The chapter begins with the well-known story of the first use of penicillin. Thepenicillin story is revisited in the literacy activity at the end of this chapter. Youcould use either or both of these to begin a discussion on the enormous impactthat the use of antibiotics has had on our health and life expectancy – somethingthat it is often difficult for pupils to appreciate.

What are micro-organisms?Only three types of micro-organism are included here: protoctists (protozoa andsingle-celled plants) are not mentioned. You could include these, too, if you wish.The descriptions of their structures will help pupils to reinforce their knowledge ofthe structure of animal and plant cells. Worksheet G1, Different kinds of micro-organisms, asks pupils to select information from the illustrations and words onpages 94–96 and reorganise it into a comparison table.

Worksheet G2, Growing micro-organisms, is a very simple method for growingmicro-organisms from the air on agar jelly. You could discuss with pupils what‘sterile’ means, and how the Petri dishes and the agar have been sterilised. Theyshould understand that, as soon as they touch the outside of the dish, it is nolonger sterile.

As with all practical work, risk assessments are required and, in this topic,school-based training in aseptic techniques may be necessary. Do not allowstudents to breathe over the open dish, or to touch the agar jelly, as thiscould result in potentially harmful micro-organisms being cultured.

The dishes should be sealed to ensure the tops cannot come off accidentally, andremain sealed through to safe disposal. Store the sealed dishes upside down, toavoid water droplets condensing on the lid and falling onto the surface of theagar. The dishes should be incubated at about 25 °C, or room temperature, sothat the growth of pathogenic bacteria is not encouraged.

When examining the dishes, the lids must not be removed. After use, dispose byan appropriate method of sterilisation.

‘Furry’ colonies growing on the agar are fungi, while smoother ones are likely tobe bacteria. Yeasts (a type of fungus) also produce smooth colonies. Somefilamentous bacteria form characteristic thin, curly threads on the agar surface.

Using micro-organismsThere are many different ways in which we use micro-organisms, and only three –making bread, making yoghurt and making cheese – are described here. Otheruses that you could include are recycling garden waste by making compost,making alcoholic drinks (but take care here if this is a sensitive cultural issue inyour school) or making ‘single-cell protein’ such as Quorn.

Most pupils will already know that yeast is used for making bread. WorksheetG3, Detecting respiration in yeast, will help them to revise the respiration equationand how carbon dioxide can be detected. They can then move on to using yeastrespiration in bread-making. Worksheet G4, How does yeast affect bread dough?,employs a simple (and not very reliable) method for comparing dough volumeswith and without yeast. Pupils can then choose to use either this technique, or amore direct measurement of yeast respiration without the complication of flourand dough-making, in their own experiment in Worksheet G5, Investigating theeffects of different concentrations of sugar on yeast respiration.

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All practical work with yeast works best using the ‘active’ dried yeast that is sold inmost supermarkets for use with bread-making machines. If the yeast suspension ismade up using warm water, this too will help to speed things up. Nevertheless, itmay not be possible to get dough to rise fast enough to obtain results forWorksheet G4 in one lesson, and pupils may need to come back to the lab later inthe day to read the volumes of the dough.

For Worksheet G5, Investigating the effects of different concentrations of sugar onyeast respiration, you could supply pupils with a range of sugar solutions ofdifferent concentrations, or allow them to measure out different masses of sugar toadd to a standard yeast suspension. Some may choose to use only twoconcentrations, while others may want to use so many that the apparatus and workinvolved become far too great; you could leave them to it and let them find out forthemselves what is a suitable range to use. They may be surprised to find that highconcentrations of sugar actually inhibit the yeast; this is because water moves outof the yeast cells by osmosis. The pattern they should find is that increasing thesugar concentration increases the rate of respiration up to a point, beyond which itdecreases it. They could consider how they might then carry out a furtherinvestigation to pinpoint the optimum sugar concentration more precisely.

Most pupils will already know that micro-organisms are used to make yoghurt,though they probably will not know that these are bacteria. Worksheet G6, Usinglactose-reduced milk to make yoghurt, provides an opportunity to make yoghurt forthemselves.

Unless you can do this activity in a food preparation environment, it is notsafe for pupils to taste their yoghurt.

The worksheet asks pupils to measure the pH of their two samples of yoghurt. ThepH will change throughout the process, and if you have data-logging equipment itwould be excellent to use it here to make a record of the pH changes. Pupils mayneed reminding that a low pH indicates acidity. The pH usually changes morerapidly when lactose-reduced milk is used, probably because the lactose in thismilk has been changed into other sugars (glucose and galactose) that the bacteriacan use more readily. However, by the time the finished yoghurt has been made,there will probably not be much difference in pH.

Another change that will take place is in viscosity. This is not mentioned on theworksheet, but it could be included in the measurements that are made. A simpleway of comparing the viscosity of two yoghurt samples is to place equal volumesof them into a plastic syringe (with the plunger removed) and time how long ittakes for it to drip out through the nozzle.

Harmful micro-organismsPupils will know that micro-organisms can cause disease. They should learn to usecorrect terminology here – avoid words such as ‘bugs’, ‘germs’ and ‘catching’, andencourage the use of ‘bacteria’, ‘viruses’, ‘pathogens’ and ‘infectious’. You may liketo discuss with pupils the various causes of diseases other than pathogens – forexample genes (sickle cell anaemia), poor diet (scurvy) or just things going wrongwith our own cells and tissues, possibly influenced by our genes, lifestyles and age(cancer, heart disease).

Worksheet G7, Food poisoning, provides data for pupils to consider and evaluate.The early questions require them to practise reading values from a graph, andmaking simple calculations. They are also asked to think carefully about makingwhat looks like an obvious conclusion – do these data really mean that foodpoisoning became more common during the 1980s, or could it just be thatnotification procedures improved? In fact, most of the increase was in one type of


!


Salmonella, suggesting that the increase was real and not just a result of betterreporting or recording. Worksheet G8, John Snow and the cause of cholera, andWorksheet G9, Dr Snow's map, describe some of the evidence that led Snow tohis conclusion that cholera was transmitted by water, at a time when micro-organisms and the causes of diseases were quite unknown. There is a lot ofwritten information on Worksheet G8, and it may be better to tell this storyorally to pupils who do not have strong reading and comprehension skills. Thereis quite a lot more interesting detail that could be added, available from severalweb sites. All pupils, however, should be able to cope with the evidence on themap in Worksheet G9, and begin to appreciate how Snow used a combination ofanecdote (the woman who lived 5 miles away yet got cholera) and carefulanalysis of data (the distribution of deaths) to come to his conclusions.

Immunity is described in terms of the ability to make specific antibodies. Theterms ‘antibody’, ‘antigen’ and ‘antibiotic’ are very easily confused, and the term‘antigen’ has been deliberately avoided here in order to reduce the potentialconfusion slightly. There is no need for pupils to learn the even more confusingterms ‘active immunity’ and ‘passive immunity’, or ‘natural immunity’ and‘artificial immunity’; it is much more important to understand the basic principles.

Vaccination is always in the news, and pupils could collect newspaper articlesabout whatever is the current issue. There is also a great deal of information onthe internet. You may have to tread a careful line in discussing the advisability ofhaving the MMR (measles, mumps and rubella) vaccine if some parents arestrongly opposed to this. However, there is no doubt that vaccination has had ahuge positive impact on child health and mortality, and the World HealthOrganization (WHO) data on pages 102–103 in the Pupil Book will help toillustrate this. Pupils could also research the success of the campaign to eradicatesmallpox using vaccination (question 4 at the end of the chapter) or the currentcampaign to try to eradicate polio.

Antibiotics will be familiar to most pupils, but probably they – like most adults –will not appreciate that these drugs are useful only against diseases caused bybacteria. The well-known story of the discovery of penicillin is always worthretelling, and you may like to go into this is in more detail than is described in theLiteracy activity Lump of mould sells for thousands.

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What are micro-organisms?Sterile plastic Petri dishes are best to use for the activity in Worksheet G2,Growing micro-organisms. They are bought ready-sterilised.

Preparing agar plates: nutrient agar can be bought as powder or tablets. Add theappropriate volume of water to the powder or tablets (for example 10 cm3 to twotablets). The agar will dissolve during the process of sterilisation in a pressurecooker (or autoclave if you have one).

It is best to prepare the agar jelly in bulk, in containers that you can handle easilywhen pouring the molten agar into the Petri dishes. Generally conical flasks workwell. Do not fill them to more than one-third of the height of the flask, as thecontents may boil during heating. Plug the neck of the flask with cotton wool(non-wettable cotton wool if available), leaving enough projecting to make it easyto pull the plug out afterwards. Pressure changes during heating can suck the plugfurther into the flask.



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Load the flasks into the pressure cooker and heat to full pressure. Keep at thispressure – which should achieve a temperature of around 121 °C – for at least20 minutes. Allow to cool. You need the agar to be hand-hot, that is around 60 °C. If you let it cool too much, it will begin to solidify as you pour it,producing lumps. If it is too hot, there will be excessive condensation in the plateso that water runs onto the agar surface. Some experience is needed to judge thiscorrectly.

When the agar is ready to pour, place the sterile Petri dishes on a clean benchsurface with enough space around each one to get your fingers in to lift the lidtemporarily while pouring. Working quickly, lift a Petri dish lid with one hand justenough to allow you to pour agar into the dish. Cover the base to around two-thirds of the area. Replace the lid and gently swirl the plate so that the agarspreads to cover the base. Lift the lid again so that it is just ajar. This allows somesteam to escape, reducing the amount of condensation. Repeat with the rest ofthe plates. Then gently touch the lids to drop them into their normal position.Leave them for at least 30 minutes before use.

Take one or two of the plates and incubate them to check for sterility. If micro-organisms grow within the body of the agar, this indicates that the sterilisationprocess was not successful; perhaps the pressure and temperature were notsufficiently high, or were not held for long enough. Growth on the surface of theagar indicates that contamination from the air occurred after the plates had beenpoured.

To store the poured, sterile plates, invert them so that condensation will not droponto the agar surface. Stack them in a refrigerator until needed.

It is important not to increase the likelihood that pathogenic organismswill grow on the agar plates. Do not, therefore, deliberately introducemicro-organisms from humans into the plates, for example by lettingpupils breathe over them or place their fingers on them. Even so, you mustalways assume that there may be pathogenic organisms on the agar. It isvery important that the lids are kept firmly in place while the pupils areexamining the agar surface.

Do not incubate the plates at body temperature (37 °C) as this encourages thegrowth of micro-organisms that live inside the body. Keep them at roomtemperature, or at around 25 °C.

Using micro-organismsIt is worth trying the investigation in Worksheet G3, Detecting respiration in yeast,out beforehand, in order to determine how long it is likely to take for results tobe seen. If you find a concentration of yeast and sugar that works quickly, usingwarm (not hot) water, it should be possible to complete the activity in one lesson.Yeast from freshly opened containers or sachets will give better results than thatwhich has been exposed to the air for some time.

Note that the yeast will rapidly use up most of the oxygen available, and so willprobably be respiring anaerobically. However, there is no need for pupils to bemade aware of this; they have not yet been introduced to the idea of anaerobicrespiration. Yeast produces carbon dioxide whether it is respiring aerobically oranaerobically.

It is suggested that half the class carry out the activity in Worksheet G4, Howdoes yeast affect bread dough?, while half make yoghurt using Worksheet G6,Using lactose-reduced milk to make yoghurt. If time is available, it would beexcellent if all pupils could carry out both activities.


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Sc1

Scientific Enquiry

1c

Sc2


1e, 2n

Sc3


Sc4

Physical Processes


If you are able to carry out this investigation in a food-preparation environment,then the doughs could be baked and the pupils could taste them.

Pupils will get in quite a mess when making their dough, so be prepared for this.The quantities of flour and yeast suspension suggested can only be approximate,as different types of flour have different absorbencies. It may be worth tryingthis out beforehand to determine the best quantities to use.

Placing the dough into measuring cylinders provides a quick and simple way ofmeasuring its volume, but it is not particularly accurate as the surface of thedough is unlikely to be even. Also, there is likely to be variability in theconsistencies of the two pieces of dough, the way in which they are handled,and the force with which they are pushed into the measuring cylinder.Nevertheless, clear differences should be seen in their volumes. Once again, youmay like to pre-test this activity to determine how long it will take for results tobe obtained.

If pupils have done the investigations on Worksheets G3 and G4, they will beable to choose between these two techniques to use in Worksheet G5,Investigating the effects of different concentrations of sugar on yeast respiration. Thetest-tube investigation is simpler and therefore more likely to yield meaningfulresults, but pupils may prefer the mess of the dough-making exercise. As they areasked to find out if yeast respires faster if it has more sugar, they will need tomake measurements or observations at particular times. This could generatesufficient data to enable line graphs to be drawn.

More able pupils may suggest collecting the gas from the respiring yeast andmeasuring its volume at regular time intervals. To do this, they will need todispense with the lime water and collect the gas using a gas syringe. Collectingcarbon dioxide over water (or lime water) does not work because much of itdissolves. However, if the yeast is respiring aerobically even the gas syringemethod will not work, as the volume of oxygen taken in should equal thevolume of carbon dioxide given out. It is probably best for pupils to time howlong it takes for the lime water to go cloudy (they will need to decide how todetermine the ‘end-point’) or to count bubbles produced in a given timeinterval. Neither of these methods is very accurate, but should be adequate toprovide comparative results.

It is strongly recommended that you let pupils carry on with their own design,whatever flaws you can see in it, as they often discover these for themselvesonce they begin working and will make changes as they go along.

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What I have learnt

Microbes and disease


Yoghurt

Skin

Bacteria

Cholera

Penicillin

Bread

Antibiotic

Immunity

Mucus

Cheese

Infectious disease

Antibodies

Virus

Fungus

Yeast

Barrier

Cilia

Microbe

Vaccination

Lactic acid

Pathogen

Bacterium

Transmission

Polio

Micro-organism

White blood cells


• I know about viruses, bacteria andyeast

• I know that micro-organisms sharethe characteristics of other livingthings

• I know how to grow bacteria andfungi on agar jelly

• I know how to use micro-organismsto make things such as bread andyoghurt

• I know about the role of micro-organisms in infectious diseases

• I can design an experiment tocompare rates of respiration

• I know that pathogens are micro-organisms that can cause disease

• I know about the body’s defencesystems

• I know how immunisation canprotect against microbial infections

• I know how infectious diseases aretransmitted

• I know how vaccination works

• I know what antibiotics are

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CHECKLIST

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Lesson Focus Pupil Book 2 pp. 94–96Growing micro-organismsDifferent types of micro-organisms

ExpectationsMost Pupils Know that some micro-organisms cause disease. Know that micro-

organisms include viruses, bacteria and yeast, and that viruses aremuch smaller than bacteria. Understand how to use Petri dishesand agar jelly to grow micro-organisms, why the dish and agarshould be sterile, and why the lid of the dish must be sealed.

Less Able Pupils Know that some micro-organisms cause disease. Know that micro-organisms include viruses, bacteria and yeast. Know how to usePetri dishes and agar jelly to grow micro-organisms.

More Able Pupils All the above plus appreciate the size differences and structuraldifferences between viruses, bacteria and human cells.


Cross-curricular developmentUnit 20 ‘Twentieth-century medicine’ and unit 21 ‘Scientific discoveries’ in the history scheme of work.

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Stimulus material relating to the AlbertAlexander story (e.g. images)

Worksheet G2 Growing micro-organismsPer group:A sterile Petri dish containing sterilenutrient agarMarker pen to write on the Petri dishAdhesive tape and scissors for sealing thedish

Worksheet G1 Different kinds ofmicro-organisms

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10 In and register. More able pupils may be able to name viruses, Pupils know that bacteria can cause illness and death, and Starter. Tell pupils the story of Albert Alexander, and so introduce the idea of and possibly yeast, as examples of micro- begin to think about the importance of micro-organisms.bacteria causing disease and the use of antibiotics. Move on to explain that most organisms.micro-organisms do not cause disease. Explain that very small organisms such as bacteria are called micro-organisms, and ask pupils if they can name any other micro-organisms besides bacteria.

10 Development. Hand out Worksheet G2 Growing micro-organisms. Show Pupils learn the meaning of the term ‘sterile’.pupils the apparatus they will use, and explain the meaning of the term ‘sterile’. Safety – emphasise the need to tape the lid of the Petri dish to the base.

15 In groups, pupils set up Petri dishes as in Worksheet G2, leaving them in a safe Pupils use Petri dishes and agar jelly to grow bacteria.place for next lesson.

15 Plenary. Using the images on pages 94–96 in the Pupil Book, and any other More able pupils should appreciate the structural Pupils are able to name bacteria, viruses and yeast as types of images available, discuss with pupils the different kinds of micro-organisms. differences between viruses, bacterial cells, animal micro-organisms. They begin to appreciate the differences in Distribute Worksheet G1 Different kinds of micro-organisms. cells and plant cells. size between viruses and bacteria.

Homework: Complete Worksheet G1.


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Lesson Focus Pupil Book 2 pp. 96–97Observe colonies of micro-organisms growing on agarInvestigate respiration in yeast

ExpectationsMost Pupils Know that yeast respires, and how to detect this. Recognise the

appearance of colonies of different types of micro-organismsgrowing on agar. Know how to dispose of used Petri dishes safely.

Less Able Pupils Know how to detect the production of carbon dioxide by yeast.Recognise the appearance of micro-organisms growing on agar.Know how to dispose of used Petri dishes safely.

More Able Pupils All of the above, plus understand the reasons for the arrangementof the apparatus used to detect respiration in yeast.



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Worksheet G3 Detecting respiration inyeastPer group:Apparatus as shown on Worksheet G3 –two test tubes, bung, tubing, lime waterSuspension of yeast in a warm glucosesolution – use about 3 g of fast-actiondried yeast and 3 g of glucose in 100 cm3

of water

Petri dishes from previous lesson, plusspare copies of Worksheet G2 Growingmicro-organismsSafe means of disposal for the dishes

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10 In and register. More able pupils will volunteer information about Pupils understand that yeast respires and produces carbon Starter. Remind pupils that yeast is a micro-organism, and ask them to suggest respiration, and relate this to what they will dioxide.ways in which we use yeast. Distribute Worksheet G3 Detecting respiration expect to happen in the apparatus. Pupils reinforce their knowledge that lime water is used to test in yeast. Talk through the worksheet, asking pupils what they remember about for carbon dioxide.respiration.

10 Development. In pairs, pupils set up the apparatus as shown in Worksheet G3.

15 Ask pupils to collect their Petri dishes that were set up last lesson. Discuss with Pupils interpret the appearance of their Petri dishes, and them what they can see on the surface of the agar, helping them to understand understand that micro-organisms can reproduce to form visible that single and therefore invisible micro-organisms have multiplied to form colonies. visible colonies.Instruct pupils to make a labelled drawing of their dishes, and to answer questions 1 to 4 on Worksheet G2. Help less able pupils with these tasks.

5 Collect in all Petri dishes and dispose of them safely. Ensure that pupils Pupils begin to understand the importance of avoiding understand why and how this is done. contamination and infection when working with micro-

organisms.

10 Plenary. Ask pupils to look at their apparatus set up earlier in the lesson. More able pupils will appreciate the reasons for Discuss with them what has happened, and talk through the questions on the the arrangement of the tubing in the apparatus. worksheet.

Homework: Write up the experiment on Worksheet G3, and finish answering the four questions on this worksheet.


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Lesson Focus Pupil Book 2 pp. 96–97Using yeast to make bread and bacteria to make yoghurt

ExpectationsMost Pupils Know how yeast is used to make bread and how bacteria are

used to make yoghurt. Understand that carbon dioxide fromyeast respiration makes dough expand, and that bacteriaconvert milk sugar (lactose) into acid.

Less Able Pupils Know how yeast is used to make bread and how bacteria areused to make yoghurt.

More Able Pupils All the above, plus understand why pH changes as milk ischanged into yoghurt.



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Worksheet G4 How does yeast affect breaddough?Per group (half the class):Strong white bread flourYeast suspension containing about 5 g fast-action yeast per 100 cm3 of warm water, plus alittle sugarWarm water with a little sugar dissolved in itClean surface for mixing and kneading dough100 cm3 and 250 cm3 measuring cylinders

Worksheet G6 Using lactose-reduced milkto make yoghurtPer group (half the class):UHT milkUHT lactose-reduced milkLive yoghurtMeasuring cylinders or syringes to measure 1 cm3 and 10 cm3

Glass rodTwo boiling tubes and rackMethod of measuring pH (preferably a probeand data-logger)Water bath at 43 °COptional: two plastic syringes (for comparingthe viscosities of their yoghurt)

Worksheet G5 Investigating the effects ofdifferent concentrations of sugar on yeastrespiration

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10 In and register. More able pupils may be able to suggest that the Pupils know that yeast is used to make bread, and that Starter. Remind class of their work with yeast last lesson. Introduce the idea of carbon dioxide from yeast respiration helps dough bacteria are used to make yoghurt.making use of micro-organisms, and discuss with them the use of yeast to make to rise. bread, and of bacteria to make yoghurt.Distribute Worksheets G4 How does yeast affect bread dough? and G6 Using lactose-reduced milk to make yoghurt.

20 Development. Arrange the class into mixed ability groups, and allocate one of Less able pupils may have difficulty in following Pupils gain first-hand experience of either the use of yeast in these investigations to each group, ensuring approximately half the groups will the Worksheets if they have not been explained bread-making, or the use of bacteria in yoghurt-making.do each one. Ask each group to carry out their allotted investigation. Support the first. More able pupils are likely to lead the groupsgroups as they work. in carrying out the investigation.

10 When all groups are at a ‘waiting’ stage, ask one pupil working on the bread Pupils know the method for whichever process they have not investigation and one working on the yoghurt experiment to explain to the rest worked with themselves.of the class what they are doing.

5 Make clear arrangements for a pupil from each group to return to collect more results later in the day, if necessary.

5 Plenary. Distribute Worksheet G5 Investigating the effects of different Pupils begin to think about designing an investigation into the concentrations of sugar on yeast respiration. Discuss this briefly to get pupils effect of one factor on the rate of respiration in yeast.on the right track with their planning.

Homework: Worksheet G5 – pupils plan an investigation that they will carry out next lesson.


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Lesson Focus Pupil Book 2 pp. 96–97A planned investigation into the effects of sugar concentration on the rate of yeastrespiration

ExpectationsMost Pupils Contribute positively to group discussion about their experimental

design, and to carrying out the investigation. Make a clear andappropriate record of their method, results and conclusions.

Less Able Pupils Make some contribution to group discussion about experimentaldesign, and to carrying out the investigation. With help, make arecord of their method, results and conclusions.

More Able Pupils All the above, plus play a leading role in deciding on the best wayof carrying out the investigation, and in carrying it out. Makesuggestions for improvements in the design either while carryingout the investigation, or when writing up afterwards.



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Worksheet G5 Investigating the effectsof different concentrations of sugar onyeast respirationPer group:Apparatus as for Worksheets G3 and G4– see lesson plan 3Top pan balanceSucroseGlucoseSpatula

Spare copies of Worksheets G3 and G4in case anyone has lost theirs

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5 In and register. Less able pupils may not have a record of results, Pupils have a complete set of results for their investigation Starter. Remind pupils of their investigations into bread-making and yoghurt- and will be given the opportunity to obtain these into either bread-making or yoghurt-making.making last lesson. Ensure each pupil has a set of results from their activity, from other members of their group.which will be needed for their homework.

5 Development. With the class, discuss ideas for the plans using Worksheet G5 More able pupils are likely to lead the Pupils work cooperatively to decide on the best way of Investigating the effects of different concentrations of sugar on yeast decision-making process. Less able pupils may carrying out their investigation.respiration. Arrange pupils into groups, and ask them to decide on the plan not have made much headway with their which the group will follow. planning, and will be led by other members of

their group.

30 Ask each group to carry out their planned investigation. Once the experiment is Less able pupils will need encouragement to make Pupils carry out their group’s plan. They reinforce their under way, each pupil should use waiting time to begin writing up the method a positive contribution to their group’s activity. understanding of the need to control variables, and how to and results of their investigation. Ensure each member of the group obtains a collect, record and display results to try to answer a question.complete set of results.As they work, discuss with each group what they are doing, and how they are recording and displaying their results.

10 Plenary. When sufficient results are obtained, ask pupils to clear away Pupils have a record of the method, results and conclusion of apparatus, settle and complete their write-up of their investigation. their investigation.

Homework: If necessary, complete the write-up of this investigation. Write up the experiment from Worksheet G4 or Worksheet G6.


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Lesson Focus Pupil Book 2 pp. 98–100How the body defends itself against pathogens

ExpectationsMost Pupils Know the meaning of the term ‘pathogen’, and understand some

ways in which pathogens can enter the body. Know how the bodydefends itself against entry of pathogens, and how white bloodcells destroy pathogens that have got past these defences.

Less Able Pupils Use the term ‘pathogen’, and know some of the ways in whichpathogens enter the body. Be able to state at least two ways inwhich the body prevents entry of pathogens. Know that whiteblood cells help to destroy pathogens.

More Able Pupils All the above, plus use imaginative ways of illustrating barriers andresponses to infection.



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If available, stimulus material such asphotographs or video clips relating toinfection and the body’s defencemechanisms against pathogens

Worksheet G7 Food poisoning

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5 In and register. Pupils learn the meaning of the term ‘pathogen’.Starter. Remind the class of the work they have done with useful micro-organisms. Help them to think back to the Albert Alexander story, and use this to introduce the idea of harmful micro-organisms and the term ‘pathogen’.

5 Development. Using the illustration on page 98 in the Pupil Book, discuss the More able pupils are likely to volunteer Pupils understand how pathogens can enter the body.ways in which pathogens can get into the body. Prompt pupils by asking information. Less able pupils will be encouraged questions such as: ‘How do you catch a cold?’, ‘What might give you a stomach to contribute to the discussion.upset?’, ‘Why should you clean a cut?’

15 Ask pupils to suggest ways in which the human body stops pathogens getting in Less able pupils can copy the illustration on page Pupils know some of the ways in which the body prevents the through each of these routes and discuss these with the class. Ask them to make 98 in the Pupil Book, but add their own entry of pathogens. They revise their knowledge of some parts an outline drawing of a person in their workbooks, and to annotate it to show annotations. More able pupils can be encouraged of the digestive and gas exchange systems.these barriers, using page 98 in the Pupil Book to help them. to be more original in their approach.

5 Ask pupils to answer question 1 on page 99 of the Pupil Book in their Pupils apply general understanding of methods of infection to workbooks. specific situations.

5 Using the illustrations on pages 99–100 of the Pupil Book, discuss with the class Pupils know that white blood cells defend against pathogens.how white blood cells defend the body if pathogens do get in.

15 Plenary. Ask pupils to answer question 2 on page 100 of the Pupil Book in their Less able pupils can copy the illustrations in the Pupils reinforce their understanding of some terminology workbooks, and to illustrate their answer with cartoons showing how the two Pupil Book. More able pupils can be encouraged associated with the immune response.types of white cell act against pathogens. to invent their own drawings. Distribute Worksheet G7 Food poisoning.

Homework: Worksheet G7.


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Lesson Focus Pupil Book 2 –Dr John Snow and the discovery of the cause of cholera

ExpectationsMost Pupils Know how John Snow collected and used evidence to find the

source of cholera infections. Understand that cholera is transmittedin water and caused by bacteria.

Less Able Pupils Know that John Snow discovered the source of cholera. Understandthat cholera is transmitted in water.

More Able Pupils All the above, plus appreciate the importance of Dr Snow’s work ata time when little was known about the causes of infectiousdisease.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Reading and understanding information presented as continuous prose.Numeracy: Extracting numerical data from a map.ICT:


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Worksheet G8 John Snow and thecause of cholera

Worksheet G9 Dr Snow’s mapAny other available stimulus materialrelating to this story, for example videoclips, images from the internet,photographs, portraitsRulers and compasses (for drawing circleson the map)

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10 In and register. Pupils appreciate that in 1854 little was known about the Starter. Tell the class the story of how John Snow discovered that cholera was causes of infectious diseases.spread by water, using the information on Worksheet G8 John Snow and the They begin to appreciate how careful analysis ofcause of cholera and other stimulus material. numerical, and sometimes anecdotal, evidence can lead

to answers to questions.

15 Development. Distribute Worksheet G8, and ask each pupil to read it quietly. More able pupils will provide more complete Pupils reinforce their understanding of how evidence can be Then discuss with the class the answers to questions 1–4. Ask pupils to answer answers to questions, using their own words. used to answer a question. these questions in their workbooks. Less able pupils will need to be encouraged to Pupils appreciate the importance of a clean water supply in

answer in their own words rather than copying reducing the incidence of some infectious diseases.directly from the worksheet.

15 Distribute Worksheet G9 Dr Snow’s map. Ask pupils to answer the questions Less able pupils may need help with drawing Pupils make a numerical analysis of some of the data available in their workbooks. circles of a particular radius. They may find to Dr Snow. They see patterns in data which at first sight may

question 4 difficult, and require help. look fairly random.

10 Plenary. Ask pupils to make a large, illustrated notice that Dr Snow might have Pupils reinforce their understanding of the transmission of fixed to the Broad Street pump, explaining to people why the handle had been cholera through water supplies, and of Dr Snow’s work.taken off.

Homework: Complete the notice. If time, answer question 1 on page 106 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 101–103ImmunityThe use of antibiotics and the discovery of penicillin

ExpectationsMost Pupils Understand how infection with a pathogen, and vaccination, can

lead to immunity. Know how penicillin was discovered, and whyantibiotics are not used against every infectious illness.

Less Able Pupils Know that having an illness, or being vaccinated, can lead toimmunity. Know something of how penicillin was discovered.Know that antibiotics are used to treat diseases caused by bacteria.

More Able Pupils All the above, plus appreciate the huge impact that the discoveryof antibiotics had on people’s lives.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Extracting data from a graph.ICT:


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Stimulus material (images, video clips)relating to vaccination, and to thediscovery of penicillin

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10 In and register. More able pupils should now be fluent in the use Pupils understand how cloning of white cells brings about Starter. Remind pupils of their work in the lesson before last, on the role of of specialist terms such as ‘pathogen’ and immunity to a particular disease. white blood cells in destroying pathogens. ‘antibody’. Less able pupils may still use terms Using the graph on page 101 in the Pupil Book, discuss what happens when you such as ‘germs’.are infected by a pathogen that is new to your body. Explain how you become immune to a disease.

5 Development. Ask pupils what they know about vaccinations. What vaccinations More able pupils may wish to discuss any issues Pupils understand how vaccination results in immunity.have they had? Can they suggest how they work? Draw out a simple explanation currently in the news relating to vaccination.of vaccination.

15 Ask pupils to answer question 3 on pages 102–103 in the Pupil Book, and also Less able pupils may need help in understanding Pupils reinforce their understanding of immunity.question 4 if they have time, in their workbooks. the difference between ‘describe’ and ‘explain’ in

questions 3a and b.

15 With the class, discuss the use of antibiotics in curing diseases caused by bacteria, Less able pupils may need reminding that a cold Pupils revise the meaning of the term ‘antibiotic’. They including the answer to question 5 on page 103. Refer back to the Albert is caused by a virus, not a bacterium. appreciate the huge impact of the discovery of antibiotics on Alexander story, and tell the story of the discovery of penicillin, using stimulus the treatment of infectious diseases, and know something of material as available. the role of the leading contributors to the discovery and use of

antibiotics.

5 Plenary. Ask a pupil to read aloud the Literacy activity ‘Lump of mould sells for Pupils reinforce their appreciation of the importance of the thousands’ on page 104 in the Pupil Book. discovery of penicillin.

Homework Answer question a, and also b if time, of the Literacy activity on page 104 in the Pupil Book.


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ExpectationsMost Pupils Demonstrate secure knowledge and understanding of microbes and

disease.

Less Able Pupils Demonstrate some understanding of microbes and disease.

More Able Pupils All the above, plus use knowledge and understanding to interpretexperimental results.



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30 In and register. More able pupils will answer more questions Pupils consolidate knowledge gained by completing theHand out the End of Unit test, and ask pupils to complete this. correctly and will attempt the extension question. End of Unit test.

20 Do question 3 on page 106 of the Pupil Book. Pupils reinforce their understanding of the reasons why antibiotics should not be used for treating every illness.

Homework: Complete the poster.


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UN I T

Copy and complete this table. Write ‘yes’ or ‘no’ in each box. The first linehas been done for you, and there isn’t anything else to be done for the viruscolumn.

G1 Different kinds of

micro-organisms

CHAPTER

WORKSHEET1

7


Feature Virus Bacterium Yeast Animal Plant(fungus)

Are they madeof cells? no yes yes yes yes

Are they madeof more thanone cell?

Do the cellshave a cellmembrane?

Do the cellshave cytoplasm?

Do the cellshave a nucleus?

Do the cellshave a cell wall?

Is the cellwall made ofcellulose?

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G2 Growing micro-organismsCHAPTER

WORKSHEET2

7


One individual micro-organism is too small to see without a microscope. Butif you let micro-organisms reproduce then they will form a group, called acolony, that is big enough to see.

You are going to grow some micro-organisms on a kind of jelly made fromseaweed. It is called agar jelly. Agar jelly is a good food for micro-organisms.

You will grow your micro-organisms in a container called a Petri dish. Thedish and the agar must be sterile. This means that any life on them has beencompletely destroyed.

1 Collect a sterile Petri dish containing sterile agar jelly. Take the lid off thedish, and place the open dish near to a window. This gives a chance formicro-organisms in the air to fall onto the jelly.

2 After 5 or 10 minutes, put the lid onto the Petri dish again.

Use sticky tape to fasten the lid securely to the base of the dish, like this:

3 Label your dish with your name and the date. Then leave it in a safe placeuntil next lesson.

1 Did any micro-organisms grow on your dish? Make a diagramof the surface of the agar jelly.

2 Where did these micro-organisms come from?3 Why couldn’t you see the micro-organisms when they first got

onto the jelly?4 What do you think has happened so that you can see them

now?

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agar jelly

Taping the lid to the base(Petri dish upside down)

!


Yeast is a living organism. Like you, it gets the energy it needs to stay aliveby respiration.

If we detect carbon dioxide being produced by yeast, then we know that it isrespiring.

Set up your apparatus like this, and leave it in a warm place.

UN I T

G3 Detecting respiration in

yeast

CHAPTER

WORKSHEET3

7

1 What did you see happening in the apparatus? Whathappened to the lime water?

2 Suggest another liquid you could have used to detect carbondioxide.

3 Why did the apparatus need a bung in the tube containingthe yeast?

4 What do you think might have happened if you put a bungwith no holes in it into the top of the tube containing theyeast?

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yeast suspensionand glucose

lime water

273

UN I T

G4 How does yeast affect

bread dough?

CHAPTER

WORKSHEET4

7


You are going to make some bread dough with yeast, and some withoutyeast.

1 Collect about 75 g of white flour, and 50 cm3 of yeast suspension containinga little sugar. Mix them all up together and knead them to make a ball ofstretchy dough.

2 Now make a second ball of dough, but this time use 50 cm3 of sugarsolution instead of the yeast suspension.

3 Push each ball of dough into the bottom of a measuring cylinder. Recordthe volume of each ball of dough.

4 Leave the doughs for at least an hour, in a warm place. Then record theirvolumes again.

5 What can you conclude from this investigation? Suggest an explanation forany differences between the two pieces of dough by the end of yourinvestigation.

Tip:If your dough is

really sticky, then

add a little bit

more flour. If it is

really hard and

dry, then add a

little bit more

water.

You are going to plan and carry out an experiment to try to answer thequestion:

Does yeast respire faster if it has more sugar?

You could use the apparatus from Worksheet G3, or you could make doughas in Worksheet G4.

You will need to make decisions about each of these things:

• What are you going to vary in your experiment? How will you do this?

• What are you going to keep the same in your experiment? How will youdo this?

• What are you going to measure? When will you measure it? How will youmeasure it?

• How will you record and display your results?

When you actually begin to do your experiment, don’t be afraid to changeyour plans if you can see a better way of doing things.

274

UN I T

G5 Investigating the effects

of different concentrations of

sugar on yeast respiration

CHAPTER

WORKSHEET5

7


275

Some of the yoghurt you can buy still contains the living bacteria that madeit. If you add some of these bacteria to milk, they will turn that into yoghurttoo.

Cow’s milk contains a sugar called lactose. Some people find that lactoseupsets their digestive systems, so they can drink milk only if most of thelactose has been changed into other sugars. This kind of milk is calledlactose-reduced milk.

You are going to try to make yoghurt with ordinary milk, and with lactose-reduced milk. You will not be able to taste your yoghurt, because it mightget contaminated with other micro-organisms or with chemicals from the lab.

Set up your apparatus like this:

G6 Using lactose-reduced milk

to make yoghurt (page 1)

CHAPTER

WORKSHEET6

7


16 APR 03

1 Measure 10 cm of 'normal' milk intoone tube and 10 cm of lactose-reduced

milk into a second tube

3

3

3 Leave them at 43 ˚C in a water bath 4 Measure the pH in each tubeevery half hour or so

2 Then add 1 cm of live naturalyoghurt into each tube. Stir them

with a clean glass rod (wash it beforeyou put it into the second tube!) and

cover them with clingfilm

3

➤continued

You will probably need to leave your tubes for about 3 or 4 hours before themilk looks thick, like yoghurt.

You may be able to use a data-logger to record the pH in the tubesthroughout the time they are in the water bath.

Write a short comparison of the yoghurt you made with the two kinds ofmilk.

276

G6 Using lactose-reduced milk

to make yoghurt (page 2)

7

CHAPTER

WORKSHEET6


Food poisoning is caused by eating or drinking something that containsharmful bacteria.

When you have food poisoning, you feel ill and may be sick. You may havestomach ache and diarrhoea.

Sometimes, you get over food poisoning in a day or so. But sometimes it canlast for several days. You may just wait until you feel better, or you may needto see your doctor.

When someone with food poisoning tells their doctor, the doctor recordsthis. This is called notification. Notification is useful because doctors can keepa check on how many cases of food poisoning there are. If a lot of cases arehappening in one town, then this may mean that a shop, restaurant or fastfood outlet is selling harmful food.

This graph shows the numbers of notifications of food poisoning in Englandand Wales in the 1980s.

277

G7 Food poisoningCHAPTER

WORKSHEET7

7


1 How many notifications of food poisoning were there in1983?

2 How many more notifications of food poisoning were there in1989 compared with 1983?

3 Andrew said: ‘There seem to have been more and morepeople getting food poisoning during the 1980s.’Jay said: ‘Maybe. But I can think of another explanation.’Suggest what Jay was thinking.

4 Imagine you are a doctor in a small town. In just one week, 14of your patients come to you with food poisoning. You wantto try to stop too many other people getting it. Whatquestions should you ask? What else might you do?

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Year1983 1985 1987 1989 1991 1993 1995 1997 1999

40 000

35 000

30 000

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In nineteenth century London, cholera was a dangerous disease. Someonewith cholera has terrible diarrhoea. So much fluid is lost from the body thatthe blood becomes thick and the person often dies from dehydration afteronly a few hours.

No one knew about micro-organisms then. People thought that diseases suchas cholera were caught by breathing ‘bad air’. But Dr John Snow did notbelieve this. He had treated many people with cholera, but he never caughtit himself.

When someone got cholera, he saw that their digestive system was affectedfirst. So he thought that perhaps the disease was caught by eating ordrinking something.

In late August 1854, a terrible epidemic of cholera hit the district of Soho, inLondon. By early September, there were more than 100 new cases each day.John Snow went to investigate. He was sure that this must be something todo with the water supply – nothing else could explain it spreading so quickly.

People did not have water piped to their houses then. Instead, they collectedwater from pumps that drew water up from wells. John Snow noticed thatmost of the people with cholera lived near to a pump in Broad Street. Wasthe water from the Broad Street pump responsible for the disease?

The real proof came when he looked into the cholera cases of people whodid not live close to this pump. He discovered that one lady who had livedfive miles away had her water specially delivered from Broad Street becauseshe liked the taste. She died of cholera.

The solution was simple. The handle was removed from the Broad Streetpump. The number of cholera cases began to fall immediately.

278

G8 John Snow and the cause

of cholera

CHAPTER

WORKSHEET8

7


1 What gave Dr John Snow his first idea that cholera might becaused by food or water, rather than by ‘bad air’?

2 Explain how his observations during the 1854 epidemic helpedto support his idea.

3 In 1854, no one knew about bacteria. What would we dotoday to test whether a water supply was transmittingcholera?

4 Suggest how the cholera bacteria were getting into the BroadStreet water.

5 Find out how the water that comes out of our taps is treated,to make sure that we do not get cholera or any other diseasesfrom it.

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In August and September 1854, Dr Snow drew a map of the streets inLondon where people were dying from cholera. Here is part of his map. Eachline on the map represents a person who died from cholera.

1 Draw a circle with a radius of 20 mm around the Broad Street pump. How many deaths are there within this circle?

2 Draw a circle with the same radius around the pump on Upper RupertStreet. How many deaths are there within this circle?

3 Use your ruler to find out which pump is closest to the lower end ofBerwick Street and Greene Court.

4 Suggest why many people living in the lower end of Berwick Street andGreene Court died of cholera.

279

G9 Dr Snow’s mapCHAPTER

WORKSHEET9

7


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1 These diagrams show three kinds of micro-organisms.

Write the letter of the micro-organism that:a is the smallest of the three ..........................................................................b is not made of a cell .....................................................................................c is a kind of fungus ........................................................................................d has a cell membrane and cytoplasm but no nucleus .................................e could be used for making bread .................................................................f might cause food poisoning ........................................................................

(6)2 Complete these sentences, using some of these words.

antibiotics antibodies bacterium disinfectant immunepathogen red vaccine virus white

A micro-organism that can cause disease is called a ......................................... .If some of these micro-organisms get into your body, they may breed andmake you ill. Your ......................................... blood cells help to defend youagainst them, by making chemicals called ......................................... .

When you have had the disease once, your body will be ready to destroy thatkind of micro-organism again, so you have become .........................................to that disease. Another way of becoming immune is to be injected with a......................................... containing dead or weakened micro-organisms.

(5)

3 Emma made some yoghurt.

She washed a pot with boiling water, then let the pot cool.

She put some milk into the pot and added something called ‘yoghurt starterculture’.

She covered the pot with clingfilm and left it in the refrigerator.

a Suggest what was in the ‘yoghurt starter culture’.

..............................................................................................................................

(1)

End of Unit test


CHAPTER

7

A B C

281

b Why was it a good idea to wash the pot out with boiling water?

..............................................................................................................................

(1)

c Why was it important to let the pot cool down before adding the milk and starter culture?

..............................................................................................................................

(1)

d Emma was disappointed to find that the milk was taking a very long time to turn into yoghurt. What could she have done to speed it up?

..............................................................................................................................

(1)

e Emma measured the pH of the milk before she put it into the pot, and found that it was 6.4. The pH of the yoghurt that she made was 5.2. What had been happening in the pot to cause this change in pH?

..............................................................................................................................

(2)

4 This diagram shows the apparatus you could use to investigate respiration inyeast.

a On the diagram, draw label lines and label:i solution containing yeastii lime water

(2)




b What else needs to be added to the yeast solution, so that the yeast can respire?

..............................................................................................................................

(1)c Describe what you will see happening in the lime water, and explain why

this happens.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(3)d How does yeast respiration help us to make bread?

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)

Total marks: 25

Extension

5 Dr Simms wanted to find out which antibiotic was most effective against aparticular kind of bacteria.

She poured a liquid containing the bacteria over some agar jelly in a Petridish. She soaked little circles of filter paper in four different antibiotics. Sheplaced the filter paper circles onto the agar jelly. She taped the lid on, andput the dish into a warm place.

colonies ofbacteria

P Q

RS



a Dr Simms made sure the Petri dish and the agar jelly were sterile before she began her experiment. Suggest why this was important.

..............................................................................................................................

..............................................................................................................................

(2)

b The clear areas around some of the discs showed that the antibiotics in these discs had stopped the bacteria reproducing and forming colonies.

Measure the diameter of the clear area around each disc. Record your results in a table in this space.

(4)c Which antibiotic was most effective at stopping the bacteria from

reproducing?

..............................................................................................................................

(1)d Suggest how the molecules of antibiotic had spread out into the agar

jelly around the discs.

..............................................................................................................................

..............................................................................................................................

(2)e Explain why antibiotics are no use for curing ’flu.

..............................................................................................................................

..............................................................................................................................

(1)




Text answers1 a Food poisoning

b Cholera, polioc Cold, ’flud Tetanus

2 Pathogens, white, cytoplasm, antibodies3 a The number of reported cases of measles generally decreased between

1980 and 1989. (Pupils should not try to describe every little increase or decrease along the way; the general trend is definitely downwards.) Some pupils may also recognise that the drop in the number of cases was initially very steep, becoming less steep in the 1990s.

b The percentage of children being vaccinated against measles rose between 1980 and 1990, and then stayed steady at about 80%. As more children were vaccinated, fewer children got measles.

c In some countries, it is just too difficult to get vaccine to every child. This is especially true in developing countries. Wars can stop medical aid getting through.

4 a The antibodies pass from the mother’s blood to the fetus’s blood across the placenta.

b Breast milk contains antibodies from the mother. A breast-fed baby has immunity to the diseases its mother is immune to.

c Antibodies do not last very long. The baby’s own white blood cells have not ‘learnt’ to make antibodies, so once its mother’s antibodies are gone then so has the immunity. The baby cannot get long-lasting immunity until its own white cells have been exposed to the pathogen, either by having a disease or by being vaccinated.

5 A cold is caused by a virus. Antibiotics only work against bacteria.


Answers will vary.


1 a Yeastb Antibodyc Antibioticd Breade Lacticf Nucleusg Pathogenh Virusi Acidj Cilia

2 a The baby has antibodies from its mother, which it acquired while it was in the uterus.

b Each white cell can only make one kind of antibody, and each antibody can only act against one kind of pathogen. Antibodies against the measles virus are useless against the polio virus.

Microbes and diseaseC

HAPTER

7

ANSWERS


Worksheet anwers

G1 Different kinds of micro-organisms

G2 Growing micro-organisms2 They had dropped onto the jelly from the air.3 Individual micro-organisms are too small to see.4 They have divided over and over again, forming colonies of hundreds of

thousands of individual cells.

G3 Detecting respiration in yeast1 Bubbles should be seen, and the lime water should go cloudy.2 Hydrogencarbonate indicator.3 To make sure that the gas produced was carried along the tube into the

lime water, rather than just escaping into the air.4 The pressure might have built up inside the tube, pushing the bung off.

G7 Food poisoning1 17 5002 (32 500 so) 15 000 more3 Perhaps more people have been going to the doctor with food poisoning,

rather than just putting up with it. Perhaps doctors are being more efficientat recording cases of food poisoning.

4 Interview the patients to find out what they have been eating and wherethey bought it from. Try to find a pattern in this information. Get inspectorsto investigate any food outlets where several of them have bought food andtest the food to see if it contains harmful bacteria. Stop any food outletwhere there are real grounds for suspicion from selling any more food untilall the checks have been made.

Chapter 7 Answers

Feature Virus Bacterium Yeast Animal Plant(fungus)

Are they madeof cells? no yes yes yes yes

Are they madeof more thanone cell? no no yes yes

Do the cellshave a cellmembrane? yes yes yes yes

Do the cellshave cytoplasm? yes yes yes yes

Do the cellshave a nucleus? no yes yes yes

Do the cellshave a cell wall? yes yes no yes

Is the cellwall made ofcellulose? no no yes


G8 John Snow and the cause of cholera1 He noticed that he did not get cholera even though he was often breathing

the same air as his patients. Also, he noticed that it was the digestive systemthat was affected first when people got cholera.

2 He guessed that the only way the disease could spread so quickly was if itwas in water. He calculated that most deaths were close to the Broad Streetpump. He found out that a woman who lived many miles away who died ofcholera had used water from the Broad Street pump. (He also noticed thatno one in the Brewery in Broad Street died – he found out that they neverdrank water, only beer. And no one in the Workhouse in Broad Street diedeither – he found out that they had their own well.)

3 Take a sample of water and look at it under a microscope to see if itcontains cholera bacteria. Spread some of the water onto agar jelly and seeif cholera bacteria grow.

4 The water was probably contaminated with waste from the bodies of peoplewho were infected with the cholera bacterium. (In fact, the well was foundto be contaminated with sewage.)

5 The water is treated with chlorine, which kills bacteria.

G9 Dr Snow's map1 88 (but you could accept a number near this as the circle cuts through a

group of 4)2 63 The Upper Rupert St pump is closest.4 These people must have been getting their water from Broad Street.

Although these streets are closer to the Upper Rupert St pump than theBroad Street pump as the crow flies, in terms of distance to be walked theBroad Street pump might be closer. Or perhaps people preferred the taste ofthe water from the Broad Street pump. Perhaps the streets on the way tothe Broad Street pump were more pleasant or less dangerous to walkthrough than the ones on the way to the Upper Rupert St pump.


1 a Bb Bc Cd Ae Cf A (6)

2 Pathogen; white; antibodies; immune; vaccine (5)3 a Bacteria (1)

b To destroy/kill any bacteria already present (1)c So that the starter culture/bacteria being added would not be killed (1)d Left it somewhere warmer (than a refrigerator) (1)e An acid had been produced; lactic (acid) (2)

4 a Solution containing yeast labelled in left hand tube; lime water labelled in right hand tube (2)

b Sugar/glucose (1)c Bubbles; goes cloudy; carbon dioxide produced by yeast (3)d Production of carbon dioxide makes the dough rise (2)

Total marks: 25

Chapter 7 Answers

287

Extension question

5 a So that there were no bacteria/fungi on it; she only wanted to test one particular kind of bacterium (2)

b

Table can be clearly understood; table has clearly headed rows and columns; units are in the heading (not in the body of the table); all measurements are correct (4)

c Q (1)d Diffusion; random movement of particles (2)e ’Flu is caused by a virus/antibiotics do not kill viruses (1)





Chapter 7 Answers

Disc Diameter of clear area/mm

P 0 (allow if disc itself has been measured)

Q 16

R 8

S 14

Pupils should be familiar with the following ideas:• Temperature is a measure of how hot an object is• How to use a thermometer• Metals are good thermal and electrical conductors• Evaporation occurs at the surface of a liquid• The particle model of matter• Differences between solids, liquids and gases

8 Heating and cooling

288

QC

A S

ch

em

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f W

ork

Re

fere

nc

e:

Un

it 8

I

Starting points


BoilingBoiling pointCelsius scaleCondensingConductionContractionConvection current

DensityExpansionFreezingFreezing pointHeat energyInsulationMelting

Melting pointScale of

temperatureSolidifyingTemperatureThermal

Thermal conductor

Thermal insulatorThermal radiationThermometerVacuum

In this topic pupils should learn:• about the need for a temperature scale• to distinguish between heat (as energy) and temperature• about the mechanisms of heat transfer – conduction, convection and radiation

– and apply this to familiar contexts• about expansion and change of state in solids, liquids and gases• to use the particle model to explain conduction, convection and change of state• to draw and interpret line graphs from data collected• to investigate the effectiveness of different forms of insulation, controlling

relevant variables

Learning checklist

Links

10HRS

TE

A C H E R N OT

ES

Links with the Key Stage 2 Scheme of WorkUnit Title4C Keeping Warm5D Changing State


CH A P T E R

8

T I M I N G

289


?b

ca

=8

2+

Most pupils

Scientific enquiry• Plan a survey of perceptions of temperature, using an appropriate sample• Plan an investigation into methods of reducing heat loss• Carry this out using ICT for recording temperature data and relate findings to

practical implications• Select effectively information from secondary sources to compare methods of

preventing heat loss in houses• Collect and interpret temperature data from a substance changing statePhysical processes• Give examples of common temperatures on the Celsius scale• Distinguish between heat and temperature• Describe energy flow as the result of temperature difference• Describe some uses of good conductors and insulators• Give examples of conduction in solids and convection in liquids and gases• Explain conduction and convection, expansion and change of state in terms of

the particle model

Pupils who have not made so much progressScientific enquiry• Use thermometers safely• Present survey data using a chart or table• Identify and control key variables in an investigation of insulators for reducing

heat loss and draw practical conclusions• Select information to report on ways of reducing heat loss in houses• Draw a graph of temperature changes when a substance changes statePhysical processes• Give examples of some common temperatures• Describe some uses of good conductors and insulators• Describe how insulators can reduce heat loss• Describe how substances expand and change state

Learning outcomes


Links with other Units in the Key Stage 3 Scheme of WorkUnit Title7G Particle Model of Solids, Liquids and Gases7I Energy Resources9I Energy and Electricity


LiteracyThere is a literacy activity about life under the ice in the Pupil Book.

NumeracyLine graphs are drawn and interpreted from data collected.

290


TemperatureMost pupils will already have a good grasp of what a temperature is. They willhave often seen and heard temperatures being mentioned during a weatherforecast. Most will also know that a thermometer is an instrument used tomeasure temperatures. But few will have a firm idea why we need thermometers.The experiment with the bowls of water (Worksheet H1, How hot is it?) and theexperiences of the three people in London (described on page 107 of the PupilBook) should show pupils how poor and unreliable we are at judgingtemperatures, and hence the need for thermometers.

ThermometersThe idea of a scale of temperature, and in particular the Celsius scale oftemperature, is reinforced by looking at a temperature line and, time andequipment permitting, carrying out the experiment described on Worksheet H2,Making a scale of temperature. Pupils should be familiar with some of the mostcommon temperatures, e.g. freezing point and boiling point of water, roomtemperature. From here it can be established that there are lots of different kindsof thermometer. Which one is used depends upon the temperature we want tomeasure and its situation: in a furnace, inside a body and so on.

Why do things get hotter or colder?Using the idea of ‘why do we put something in an oven or in a freezer?’ we cantease out the idea that when things are cooling down heat energy is flowing outof them and when something is warming up heat energy is flowing into them.This neatly leads to the topic of conductors and insulators.

Conductors and insulatorsIt is simple to use familiar utensils and situations, e.g. from a kitchen, todemonstrate that we use conductors where we want good/fast transfer of heatand we use insulators where we want to stop/slow down the transfer of heat. Theplastic/wooden handled saucepan is an excellent example which is designed forboth good and poor heat transfer. Within this topic pupils should become familiarwith lots of materials that are examples of conductors and insulators. The section‘Feeling cold!’ on page 111 of the Pupil Book provides an opportunity to explainhow we are affected by heat transfer in a situation that all pupils will haveexperienced. If the rate of heat loss from the body/or part of the body is high wefeel cold, and if the rate of heat loss is small we feel relatively warm.


Pupils who have progressed furtherScientific enquiry• Make systematic measurements of temperature changes with a precision that

enables reliable conclusions to be drawn in an investigation of insulators• Evaluate different sources of information on domestic heat loss prevention

methods• Extrapolate from temperature data on change of statePhysical processes• Give examples of a wide range of temperatures on the Celsius scale• Compare conductivity of materials and relate this to their uses• Use the particle model to explain change of state relating this to the forces

between particles

291

Conduction in liquids and gasesLiquids and gases are usually poor conductors of heat (mercury being an obviousexception). The ice and boiling water in a tube experiment demonstrates this wellfor liquids and there are many examples of air (a gas) trapped within a structurebeing used for its thermal insulating properties, e.g. double glazing, fibreglass,woven materials, birds’ feathers. Worksheet H3, Keeping it hot, is a fun experimentwhere pupils can use their knowledge of insulators to try to keep a beaker of wateras hot as possible for as long as possible.

The particle model of conductionHaving identified the comparative conductivities of solids, liquids and gases, thissection of work attempts to explain these differences using the particle model.

Expansion and contractionChange in size caused by heating or cooling can be explained using particle theory.Thermal expansion and contraction can create problems, particularly for largeobjects. Allowances therefore must be made for changes in size due to changes intemperature. Two such examples – bridges and road surfaces made from concretesections – are covered on page 114 of the Pupil Book. Several examples of thermalexpansion used to our advantage are also dealt with, including the bimetallic strip.Worksheet H4, The bimetallic strip, provides pupils with the opportunity to see theeffects of increase in temperature on a bimetallic strip and help them understandhow it can be used in devices such as thermostats.

Thermal expansion of liquids and gases can be easily demonstrated as described onpage 116 of the Pupil Book and again this can be explained using particle theory.This idea can now be expanded to explain that changes in temperature causechanges in volume, which inevitably lead to changes in density. If part of a fluid isheated and becomes less dense than the surrounding fluid it will rise. This is easilydemonstrated in Worksheet H5, The spiral experiment.

Convection currentsOnce the idea of changes in temperature leading to changes in density has beenestablished, it is relatively straightforward to explain how a heat source in a liquidor a gas can create a convection current and that this movement of particlestransfers heat from the source to all parts of the fluid. The example of a storageradiator creating a convection current in air is given on page 118 of the Pupil Book.Worksheet H6, Convection currents in liquids, allows pupils to create and seeconvection currents in a liquid (water).

Potassium manganate(VII) is a harmful oxidiser – handle with forceps/tweezers.

Movement of heat energy by radiationA third method by which heat can move from place to place is by rays (radiation).Examples such as sunbathing and standing in front of a fire to warm your handsare good examples that pupils can relate to. It is important that pupils realise thatheat transfer by radiation requires no particles. It is therefore the only method ofheat transfer that can cross a vacuum. All our energy from the Sun is transferred tothe Earth by radiation.

Reducing heat loss from the homeTo bring all our ideas about heat transfer together, we now look at an uninsulatedhome and suggest ways in which we can reduce heat loss and explain why thesemethods work. Worksheet H7, Insulating your home, provides an opportunity toexplore these different methods and revise some of the main ideas in heat transfer.



!

Change of stateWhen heat enters or leaves a body, that body may increase or decrease intemperature, expand or contract. But it could, of course, change state, i.e. it couldmelt, freeze, boil or condense. On pages 121 and 122 of the Pupil Book there areheating/cooling curves for several bodies that have changed state. The places onthe curves where a change in state has taken place are easily identified, as thetemperature of a body remains constant until the change in state is complete.Pupils should be able to identify these plateau regions on a cooling/heating curve.Worksheet H8, Cooling curve for salol, allows pupils to construct their own coolingcurve for a hot liquid which will cool, solidify and then cool as a solid.Explanations of the shapes of the curves using particle theory might be required,especially for the more able pupil.

Brief explanations could be given:• Melting and boiling: heat entering a body is giving its particles energy to

overcome the attractive forces of neighbouring particles rather than increasingits temperature.

• Freezing and condensing: energy is being released as new structures form. Thisenergy keeps the temperature of the body from falling.

292

TemperatureUnless all the pupils in your class are Olympic swimmers there is a real dangerwith the experiment of Worksheet H1, How hot is it?, of someone getting intodifficulties with so much water sloshing around. This problem can be eased byusing bowls or buckets that are quite deep and not so full that they overflowwhen the pupils put their hands in them. Putting the bowls at strategic placesaround the room, i.e. away from any electrical sockets and equipment, and pre-filling them with water of the correct temperature also helps potential problems.Every pupil will try this experiment at least once so have lots of paper towelsclose to each set of bowls.

In the second part of the experiment pupils use a thermometer. It is a good ideato check while the experiment is taking place that pupils can see and read thethermometer. Remind pupils before they start to put their thermometerssomewhere safe, i.e. not next to the very edge of the desk!

ThermometersThe exercise in Worksheet H2, Making a scale of temperature, is not absolutelynecessary but if there is time and you have the equipment it is well worth doing.The ice used must be melting and so should be taken out of the freezer andcrushed about an hour before the lesson. Measuring the temperature of boilingwater always has the potential of being more hazardous than it first seems.Emphasise to pupils before starting that hair must be tied back, ties tucked in,etc., and since the water in the beaker is going to be very hot they should movethemselves and their books as far away from the equipment as possible.

Sometimes pupils burn their hands when they try to measure the temperature ofwater being heated by a Bunsen burner. This is because they hold theirthermometers so they are vertical. It is worth telling pupils to hold theirthermometers at 45° so that their hands are not directly above the Bunsen flame.



293


If time is tight you may want to consider splitting the class in two, one half doingthe boiling water part of the experiment first and the other half doing themelting ice. The two halves can then change over. Doing this reduces the numberof beakers of boiling water needed and saves time as the water from the first halfshould still be at or close to boiling point.

If the subdividing and creation of the scale is too complicated for some pupils,encourage them to estimate the temperature shown on their thermometer.

Conductors and insulatorsOnce pupils have grasped the idea that the temperature of an object falls if heatis flowing out of it, it is a good time to put another myth to sleep. You mightwant to suggest to pupils in the interest of spreading scientific knowledge that‘When their Mum or Dad next tells them to shut the door as they are letting thecold in, they can tell them they have got it wrong. Cold doesn’t come in ... it isheat that is going out’!

Few pupils have problems with the idea of conductors and insulators but it iscertainly true that the more examples of these materials pupils meet and knowhow they are used the better they understand this topic.

Most pupils can relate to feeling colder standing on a tiled floor than on acarpeted floor but instant reminders are always useful. Get them to hold or touchsomething metal, such as a stool leg or retort stand, with one hand andsomething non-metallic, such as a bench top or cloth, with the other. Thedifference is then immediately obvious. But beware the misconception that themetal object is colder, i.e. at a lower temperature. All the objects will be at roomtemperature.

Conduction in liquids and gasesPupils often see the ice and boiling water experiment, described on page 112 ofthe Pupil Book, but do not realise what it is showing. It is worth emphasising thatwe know water is a poor conductor because there is boiling water and ice just afew centimetres apart and there is very little heat transfer between the two,otherwise the ice would be very rapidly melting.

Some forethought about how you want to organise the experiment onWorksheet H3, Keeping it hot, might avoid lots of problems later. For exampleare you, the teacher, going to distribute the hot water? That might avoidproblems of pupils spilling very hot water. If there is a large clock with a secondhand in the room which all pupils can see then you do not need to give outstopwatches. Since there is lots of water around, perhaps you should give outscrap paper for pupils to record their results, rather than them using their exercisebooks, etc.

Do not forget that you will need lots of paper towels.

Expansion and contractionBeware the misconception that when an object is heated its particles expand, andwhen it is cooled its particles contract. One way to explain the real reason forexpansion and contraction is to sit as many pupils as possible in a single line, sideby side on a desk or free-standing bench. If pupils then sway from side to sidethe pupils on the ends of the line will almost certainly be pushed off as the restneed more room. The pupils (particles) have not increased in size. The line hasexpanded because of the increased motion.

Pupils like the bimetallic strip experiment (Worksheet H4, The bimetallic strip)but they will insist that the strip bends downwards or upwards when one side isheated and bends the opposite way when the other side is heated. They see what


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Scientific Enquiry

2a, 2d, 2e, 2g (partially), 2i (partially), 2m

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1b (partially), 1d (partially), 2c

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Physical Processes

5d, 5e (partially),5f


they expect to see rather than what is actually happening. Marking the sides Aand B and then heating the strip several times in as many different ways aspossible will eventually convince them that when heated one side of the strip isalways on the inside of the curve. (This is the metal that expands less.)

When doing Worksheet H5, The spiral experiment, take note of three pieces ofadvice:• Do not make the arms of the spiral too thin; about 2 cm is fine.• Use as small a heat source as possible. If you have to use a Bunsen, adjust it so

it is a small yellow flame.• Avoid burning hands by holding the spiral over the heat source with a glass

rod.

This is a good opportunity to dispel another common misconception. The spiralturns because of the warm air above the heat source rising, not because heat isrising.

Convection currentsThe secret to the experiment in Worksheet H6, Convection currents in liquids, isgetting the crystals to the bottom of the water in the beaker without the waterbecoming coloured by them. This can be done by tipping just a few crystalsdown a narrowish glass tube or straw. It is better to add too few crystals to startwith than to add too many. It is certainly worthwhile trying this before the lessonif you have not done this experiment before. To see the convection currentclearly use as small a heat source as possible.

Change of stateYou may wish to cover this topic and the experiment described on WorksheetH8, Cooling curve for salol, in two lessons if time is available. There is a lot to do.If time is tight and only one lesson is available all this work can be coveredproviding the experiment is started almost as soon as pupils arrive. Warming thesalol until it is well above its melting point just prior to the lesson and using aclass clock with a second hand will help to start the lesson promptly. Once thetemperature measurements are under way the idea of flow of energy into or outoff an object causing a change of state can be covered.

It is vital that the whole class realise that once they have begun, they must notlift, turn or twist their thermometers when they read them. They should getthem in a good position at the beginning of the experiment and then leavethem. At the end of the experiment pupils should not remove theirthermometers from the salol. This advice will prevent a lot of thermometersbeing broken.

By the end of the lesson pupils should have a table of results and perhaps acooling curve whose shape they can now explain.

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What I have learnt

Heating and cooling


Conduction

Boiling point

Freezing point

Convection current

Solidifying

Thermal radiation

Expansion

VacuumBoiling

Freezing

Heat energy

Thermal conductor

Contraction

Melting

Scale of temperature

Temperature

Thermal insulator

Celsius scale

Density

Thermometer

Melting point

Thermal

Condensing

Insulation


• I know that our senses are poorjudges of heat, so we need to use ascale of temperature

• I know that the most common scaleof temperature used by scientists isthe Celsius scale

• I know that heat energy flows fromplaces of higher temperature toplaces of lower temperature

• I know that heat energy can moveby conduction, convection andradiation

• I know about expansion andchange of state in solids, liquidsand gases

• I can use the particle model toexplain conduction, convection andchange of state

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Lesson Focus Pupil Book 2 p. 107Measuring hotness/temperature

Expectations

Most Pupils Know we cannot accurately measure how hot something is usingour senses. Know we use thermometers to measure temperaturesaccurately.

Less Able Pupils Know we use thermometers to measure temperatures.


Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Reading the temperature scale of a thermometer exactly.ICT:


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Worksheet H1 How hot is it?Per group:Three bowls of water: one hot, one coldand one lukewarm.Mercury thermometerPaper towels

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10 In and register. More able students will more readily make the Starter. Using the diagram on page 107 of the Pupil Book ask the question, connection between how warm these three people ‘Why does the Inuit in the picture seem to be warm, the Arab lady seem feel and their previous experiences.to be cold and the Englishman seem to be comfortable?’ Draw out of the class the idea that the temperatures they are experiencing at the moment are judged by comparing the previous temperatures they have experienced, i.e. the Inuit has just arrived from a very cold country and so feels very warm here in London, etc.

35 Development. Pupils can now carry out the experiment on Worksheet H1 Pupils understand that we cannot use our senses to How hot is it? measure temperature accurately.

5 Plenary. Through a Q and A session with the whole class obtain the observations Less able pupils may need some help in reading Pupils realise that to measure temperature accurately we can that we humans experience difficulties in judging how hot something is by using the scale on the mercury thermometer. use a thermometer.our senses. A more reliable way to measure hotness is to use a thermometer. Pupils know how to use a mercury thermometer.A thermometer uses a scale of temperature to measure hotness. A quick survey of the temperatures of the bowls of water as measured by their thermometers completes the lesson.

Homework: Question 2 on Worksheet H1.


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Lesson Focus Pupil Book 2 pp. 107–108Scale of temperatureDifferent types of thermometer

ExpectationsMost Pupils Will be able to create a scale of temperature and use it to measure

room temperature. Understand the need for different types ofthermometer.

Less Able Pupils Know that to measure temperatures thermometers have a scalemarked on them. Know that there are several different types ofthermometer.

More Able Pupils All the above and can understand the reasons for using differentthermometers in different situations.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Subdividing the distance between the 0 °C and the 100 °C marks on the uncalibrated thermometer.ICT:


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Worksheet H2 Making a scale oftemperaturePer group:Unmarked mercury thermometerApprox. 100 g of melting iceTwo small rubber bands to fit tightly onstem of thermometerBeaker of boiling water, produced using,e.g. Bunsen burner, tripod, gauze, beakerand heating matSafety gogglesOne piece of A4 paperOne calibrated mercury thermometer

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10 In and register.Starter. Remind pupils that we use thermometers to measure how hot something is. Thermometers have a scale marked on them which allows us to measure temperatures. Tell pupils that today they are going to be given a thermometer with no scale marked on it and that they are going to make their own temperature scale.

35 Development. Pupils carry out the experiment described in Worksheet H2 Less able pupils will need some help in creating Pupils understand what is meant by the phrase ‘scale of Making a scale of temperature. They create their own scale of temperature their scale of temperature, i.e. subdividing the temperature’ and know how one can be created.and then use it to measure room temperature. The accuracy of their scale is temperatures between 0 °C and 100 °C.then checked using a commercial thermometer.

5 Plenary. On page 108 of the Pupil Book, pupils can look at different types of Pupils realise that there are different types of thermometers thermometers and discuss how they work and why we need different types of and understand why we need them.thermometers.

Homework: Questions 1, 2 and 3 on page 108 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 109–110Direction of movement of heatConductors and insulators

ExpectationsMost Pupils Know that heat flows as a result of temperature difference. Know

that heat flows easily through conductors and not so easily throughinsulators.

Less Able Pupils Know that heat is flowing into an object that is becoming warmerand out of an object that is becoming colder. Know that heat flowseasily through conductors and not so easily through insulators.

More Able Pupils All the above and can explain why certain objects or parts ofobjects are made from thermal conductors or insulators.



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Demo: Conduction and insulationSaucepan with plastic or wooden handleLarge plastic or wooden spoonLarge, all-metal spoon

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15 In and register. Pupils understand that when objects are getting colder heat is Starter. Using the examples on page 109 of the Pupil Book discuss why things flowing out of them and when objects are getting hotter heat placed in an oven get hotter while things placed in a fridge or freezer get colder. is flowing into them. Also that heat naturally flows from hot

places to cooler places.

15 Development. In their books pupils put the heading Why do things get hotter Less able pupils may need some help in writing or colder? Then write an explanation, including diagrams where appropriate. an accurate description.

15 Using everyday items such as saucepans, wooden and metal spoons (or refer to More able students will readily recognise from Pupils understand the meaning of the phrases ‘thermal text and diagrams on page 110 of the Pupil Book) introduce the idea that their own experiences situations where conductors/ conductor’ and ‘thermal insulator’.sometimes we want heat to move from place to place and sometimes we do not. insulators are used and appreciate why they are Pupils know where such materials might be used.By making objects from different materials we can help or hinder this movement. being used in preference to other materials.Materials that allow heat to pass through them easily are called conductors, etc.

5 Plenary. Summarise main points of lesson ensuring pupils have grasped the concept of heat flow, conductors and insulators. Question 8 on page 110 of the Pupil Book may be used for this purpose.

Homework: Find out why we feel cold when we stand on a tiled floor in our bare feet but do not feel so cold if we are standing on a carpet.


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Lesson Focus Pupil Book 2 pp. 111–113Conduction in solids, liquids and gases

Expectations

Most Pupils Know that solids are good conductors of heat and that liquids andgases are poor conductors of heat. Can give examples of the usesof good conductor and insulators.

Less Able Pupils Know examples of solids that are good conductors of heat. Knowthat liquids and gases are poor conductors of heat.

More Able Pupils All the above and can explain the differences in the conductivitiesof solids, liquids and gases using the particle model.

Development of Key Skills (Literacy, Numeracy, ICT)Numeracy:Literacy: ICT:


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Demo: Comparison of conductivities ofmetalsCross consisting of four different metalbarsFour marblesCandle waxDemo: Boiling water and iceBunsen burnerBoiling tubeSmall cube of iceSmall piece of gauzeTongs or retort stand and clamp

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10 In and register. More able pupils will be able to provide a more Starter. Go over homework. Why is it cold standing bare foot on a tiled floor coherent explanation using the correct scientific but not so on a carpeted floor? There is a diagram and explanation that can be terms.used on page 111 of the Pupil Book. Using this example, remind pupils of the meaning of thermal conductor and thermal insulator and give some examples.

10 Development. All metals are good conductors but some are better than others. Pupils realise that some metals are better conductors than Using the diagram and information on page 111 of the Pupil Book, ask pupils to others.answer question 9. If the apparatus is available this can then be demonstrated.

10 Introduce the question ‘How well can heat travel through other materials that Less able pupils may need some help in realising Pupils know that water is a poor conductor.we haven’t considered yet?’, e.g. liquids and gases. Demonstrate boiling water that because there is boiling water and ice in the and ice in boiling tube. Explain why this demonstrates that water is a poor same tube separated by only a few centimetres it conductor of heat. means that water must be a poor conductor.

10 Using lots of examples, e.g. insulation brick, expanded polystyrene, fibreglass, Pupils know that gases are excellent insulators.cold weather clothing, introduce the idea that gases are also very poor conductors; in fact they are excellent insulators and often used to prevent loss of heat.

10 Plenary. As a whole class tease out how we can explain the different abilities to More able pupils will readily see the link between Pupils can explain using the particle model why solids, liquids conduct heat of solids, liquids and gases. Diagrams and explanations for this are the particle model of solids, liquids and gases and and gases have very different conduction properties.on page 113 of the Pupil Book. their differing abilities to conduct heat.

Homework: Under the heading ‘The particle model of conduction’ write an explanation of why solids are better conductors of heat than liquids and why liquids are better conductors than gases. Include diagrams with your explanations.


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Lesson Focus Pupil Book 2 pp. 112–113Insulation

Expectations

Most Pupils Can construct cooling curves and see the effect of insulation onrate of loss of heat from the water.

Less Able Pupils Can see that the insulated beaker of water cools more slowly.

More Able Pupils All the above and can give some explanation of why the rate ofheat loss is reduced by the insulation. Make valid suggestionsabout how to improve the experiment.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Use of thermometers and stopwatches. Graph drawing.ICT:


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Worksheet H3 Keeping it hotPer group:Hot waterBeaker (250 cm3)ThermometerInsulation, e.g. pieces of cotton wool,fabricSticky tapeStopwatch or clock with second handGraph paperPaper towels

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10 In and register.Starter. Remind pupils that last lesson they discovered the different abilities of materials to allow heat to pass through them. Today they are going to carry out an experiment to test the insulating properties of different materials such as paper, wool and cotton.

35 Development. Pupils read Worksheet H3 Keeping it hot, then select their More able pupils will devise more organised and insulation and decide how they are going to use it. Pupils then carry out the controlled experiments.experiment. Less able pupils may need some help in devising

an experiment that is fair and has some variable under control. These pupils may also need some help in plotting their graphs.

5 Plenary. Whole class Q and A session. Did their insulation work? How do they Insulating a warm object will slow down the rate at which it know? How well did it work? If you had to do the experiment again would you loses heat.do it the same way or would you change something? Can you compare your results with another groups? Is it fair? And so on.

Homework: Question 10 on page 112 and question 11 on page 113 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 114–115The bimetallic strip

Expectations

Most Pupils Understand that the bimetallic strip bends when heated andstraightens when cooled. Know that a bimetallic strip can be usedin a fire alarm.

Less Able Pupils Know that a bimetallic strip bends when heated.

More Able Pupils All the above and can explain why a bimetallic strip bends whenheated and straightens when cooled.



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Worksheet H4 The bimetallic stripBimetallic stripBunsen burnerHeating mat

Demo: The fire alarmThis equipment needs to be set up as acircuit before the lesson:Bimetallic stripRetort standConnecting wiresPower supplyElectric bell

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15 In and register. More able pupils will remember more examples Starter. Remind pupils why objects expand and contract when heated and and be able to relate what is happening tocooled using particle theory. Using the examples on pages 114–115 of the particle theory.Pupil Book remind them that there are advantages and disadvantages to thermal expansion and contraction.

15 Development. Introduce pupils to the bimetallic strip. Tell them it is at ‘the It may need to be pointed out to less able pupils heart’ of some very useful devices and that it makes use of thermal expansion that heating different sides of the bimetallic does and contraction. Pupils carry out Worksheet H4 The bimetallic strip. not cause the strip to bend different ways.

10 Bring the whole class down to the front and quickly establish what the bimetallic Pupils understand how the thermal expansion of the metals in strip does when heated and cooled. Demonstrate, using a simple series circuit a bimetallic strip can be used to operate a fire alarm.containing a bell, power supply, connecting wires and bimetallic strip, how a simple fire alarm can be made using the bimetallic strip. Tease out from the class how the fire alarm circuit works.

10 Plenary. Pupils write an explanation of how the bimetallic strip works (see page 115 of the Pupil Book).

Homework: Draw a diagram of a fire alarm circuit which uses a bimetallic strip. Explain how the alarm works.


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Lesson Focus Pupil Book 2 pp. 116–118Expansion of liquids and gases

Expectations

Most Pupils Know that liquids and gases expand when heated and contractwhen cooled and can explain why using the particle theory.

Less Able Pupils Know that liquids and gases expand when heated and contractwhen cooled.

More Able Pupils All the above and can explain the movement of a warmed fluid interms of its change in density.



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Demo: Expansion of liquidBoiling tube with stopper and thin tubepassing through stopperOil or waterHot water bathCold water bath

Demo: Expansion of gasRound-bottomed flask with stopper andthin tube passing through stopperBeaker of water

Worksheet H5 The spiral experimentPer group:Piece of silver foil approx. 12 cm by 12 cmScissors25 cm of threadHeat source, e.g. a candleGlass rod

Demo: Density (optional)CorkLarge beaker of water

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10 In and register.Starter. Remind pupils that over the last few lessons they have been looking at the thermal expansion and contraction of solids. Does the same thing happen if we warm or cool liquids or gases?

10 Development. Using oil or water in a boiling tube, with stopper and capillary More able pupils will readily relate the rise and Liquids expand when heated and contract when cooled.tube, demonstrate that when the liquid is heated by putting it in a hot water fall of the liquid in the capillary tube with the bath the liquid rises up the capillary tube, showing it has expanded. Placing the expansion and contraction of the liquid in the boiling tube in cold water causes the column of liquid to fall as the liquid in the boiling tube. Less able pupils may need some help boiling tube contracts. making this connection.

10 Using a round-bottomed flask with a stopper and thin tube, demonstrate that Less able pupils may again need help in Gases expand when heated.when inverted and the open end of the tube placed in a beaker of water, the understanding that when bubbles come out of the heat from a pair of hands is enough to cause the air inside the flask to expand. tube this is an indication that the air in the flask Some air therefore is pushed out of the flask and is seen as bubbles rising is expanding.through the beaker of water.

15 Pupils carry out Worksheet H5 The spiral experiment.

5 Plenary. Hold a cork at the bottom of a large beaker or tank of water, then Warmed air expands, becomes less dense than the surrounding release it. Draw out from the pupils that the cork rises because it is less dense air and so rises.than the water. Now ask what they discovered from their experiment. Why did the spiral turn? Why did the air rise? Why did the air become less dense?

Homework: Under the heading ‘The spiral experiment’ draw a diagram of the experiment and explain what happened and why.


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Lesson Focus Pupil Book 2 p. 118Convection currents in liquids and gases

Expectations

Most Pupils Can explain how a heat source can create convection currents inliquids and gases.

Less Able Pupils Know that heat sources can set up convection currents in liquidsand gases.

More Able Pupils All the above and can explain how a convection current transfersheat.



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Worksheet H6 Convection currents inliquidsPer group:Large beakerTripodCandle or Bunsen burnerDrinking straw or narrow glass tubeSpatula or tweezersPotassium manganate(VII) crystalsWater

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10 In and register.Starter. Remind pupils that last lesson they discovered that if air is warmed it becomes less dense and rises. But what happens when this air has moved away from the source of heat?

10 Development. Using the diagram on page 118 of the Pupil Book, explain how Less able pupils may need some help in A heat source can set up a convection current in a gas.these changes in density caused by a heat source can give rise to circular understanding why changes in density cause movements of air called convection currents. movements of fluids.Explain that these currents are carrying heat energy to all parts of the room. This can be demonstrated using a model mineshaft if one is available, or refer to the diagram on page 125 of the Pupil Book.

20 Pupils now carry out Worksheet H6 Convection currents in liquids. A heat source can set up a convection current in a liquid.

10 Plenary. Pupils complete diagrams showing the convection currents created in their liquid and they answer step 6 by providing an explanation of how a convection current is set up.

Homework: Question 18 on page 118 and question 3 on page 125 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 119–120Movement of heat energy by radiationReducing heat loss from a home

Expectations

Most Pupils Know that heat can be transferred from place to place by infra-redwaves. Know several different methods of reducing the heat lossfrom a home.

Less Able Pupils Know that heat can move from place to place as waves. Know thatthere are ways of reducing heat loss from a home.

More Able Pupils All the above and can explain how insulation can reduce unwantedheat transfer.



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Worksheet H7 Insulating your homeFor homework

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10 In and register.Starter. Remind class that they have investigated two ways in which heat energy can move over the last few lessons. These are conduction and convection. Point out that there is another method called radiation. This is heat energy moving by rays.

15 Development. Using the information provided on page 119 of the Pupil Book Heat energy can travel as infra-red waves, i.e. radiation. This the class can discuss examples of how heat travels by radiation. Under the is the only method by which heat energy can travel through a heading ‘Movement of heat by radiation’ pupils make notes on this topic. vacuum.

15 Using the information on page 120 of the Pupil Book pupils can explore the More able pupils will more easily relate the idea different ways in which heat can escape from a home and what can be done to of conductors and insulators to the methods of reduce this heat loss. preventing heat loss from a house.

10 Plenary. Discuss Worksheet H7 Insulating your home which is to be completed for homework.

Homework: Finish Worksheet H7.


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Lesson Focus Pupil Book 2 pp. 120–122Change of state

Expectations

Most Pupils Understand what is happening to a substance when it is melting,boiling, freezing or condensing. Can recognise on atemperature/time graph the places where these processes aretaking place.

Less Able Pupils Understand what is happening to a substance when it is melting,boiling, freezing or condensing.

More Able Pupils All the above and can explain these processes using particle theory.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Interpreting temperature/time graph.ICT: Experiment could be carried out using a temperature probe and data-logger to produce a real time graphic display.


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Worksheet H8 Cooling curve for salolPer group:Boiling tube containing hot liquid salolMercury thermometerStopwatch or clock with second handRetort stand and clamp or large beakerGraph paper

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5 In and register.Starter. Time is very tight for this lesson so tell pupils about the experiment they are going to start almost immediately. Once the experiment has started there will be plenty of time to explain what it is they are doing and why.

30 Development. Do Worksheet H8 Cooling curve for salol. Once all groups are More able pupils will more readily be able to use Pupils understand what happens to a substance when it melts, reading the temperature of the salol, explain to pupils that sometimes when heat particle theory to explain change of state. freezes, boils and condenses.flows into or out of a substance it will change state. Using particle theory, Less able pupils may be confused between theexplain melting freezing, boiling and condensing. Relate these changes to the terms ‘evaporation’ and ‘boiling’.various cooling curves and heating curves on pages 121–122 of the Pupil Book.Emphasise that boiling occurs at a particular temperature but evaporation occurs over a range of temperatures. Pupils can be reminded that they can tell when a liquid boils because they can see bubbles (as gas forms throughout the liquid). In contrast, evaporation occurs only at the surface so no bubbles are seen.

10 Pupils now draw a temperature/time graph using the readings they have just Less able pupils may need some help in drawing taken. the temperature/time graph.

5 Plenary. Discuss with pupils the shapes of the graphs they have obtained. Pupils relate shape of graph with processes that are taking place.

Homework: Sketch and label a complete heating or cooling curve for a substance such as ice/water. Explain using particle theory what is happening in the different parts of the graph.


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Lesson Focus Pupil Book 2 Chapter 8Review of topic ‘Heating and cooling’Checking pupil progress

Expectations

Most Pupils Have a good understanding of temperature scales, methods of heattransfer, expansion/contraction and changes of state.

Less Able Pupils Recognise some common temperatures, know some examples ofconductors and insulators and can describe how substancesexpand/contract and change state.

More Able Pupils All the above and can use the particle model to explain what ishappening.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Temperature scales.ICT:


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Chapter 8 End of Unit testOne set of sheets per pupil

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20 In and register. Less able pupils may need some support in Pupils reinforce their knowledge of the topics covered in this Using the Pupil Book pupils read through all the material they have covered in understanding parts of the chapter or tackling chapterthis chapter and/or they can attempt the end of chapter questions 1 and 2 some of the end of chapter questions.on page 125.

30 Sit pupils in appropriate test conditions. Pupils complete the End of Unit test. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the End correctly and will attempt the extension question. of Unit test.



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318

UN I T

1 Place your right hand in the bowl of water to your right.2 Place your left hand in the bowl of water to your left.3 Leave both of your hands in the water for about 30 seconds and think

about how hot each of the bowls of water feel.

4 After 30 seconds quickly transfer both of your hands to the bowl in thecentre.

5 What does your right hand ‘tell’ you about the hotness of the water in themiddle bowl?

6 What does your left hand ‘tell’ you about the hotness of the water in themiddle bowl.

7 Can you explain what is happening?8 Using a mercury thermometer measure the temperature of the water in

each of the three bowls.9 In your books draw a diagram of this experiment. Underneath this describe

what you did and what you discovered. Include in your description thetemperatures of the bowls of water measured by your thermometer.

H1 How hot is it?CHAPTER

WORKSHEET1

8


1 Why can’t we use our senses to measure accurately how hotsomething is?

2 Find out how a scientist would measure the temperatures ofthe following:a your bodyb the Arctic Ocean

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hot lukewarm cold

hot lukewarm cold

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UN I T

H2 Making a scale of

temperature (page 1)

CHAPTER

WORKSHEET2

8


1 Push two small rubber bands onto your unmarked thermometer.2 Place the bulb of your thermometer in a beaker of crushed, melting ice.

3 After 30 seconds move the lower rubber band until it is level with the topof the mercury column. Do not remove the bulb of your thermometerfrom the ice while you are doing this.

4 Now place the bulb of your thermometer just below the surface of abeaker of boiling water.

5 After 30 seconds move the upper band until it is level with the top of themercury column. Do not remove the bulb of your thermometer from thewater while you are doing this.

➤continued

melting ice and water

uncalibrated thermometer

beaker

rubber band marking 100 °C

rubber band marking 0 °C

pure boiling water

Bunsen burner

gauze

tripod


6 On a plain piece of paper draw a thick straight line, which is the same length as your thermometer.

7 Place your thermometer on the line and mark the positions of the two rubber bands.

8 Ice melts at 0 °C so you can write this value next to the lower mark on your paper.

9 Water boils at 100 °C so you can write this value next to the upper mark on your paper.

10 Now divide the distance between these two marks into ten equal divisions. For example, if the distance between the two marks is 14 cm then each division will be 1.4 cm long.

11 These small divisions can now be labelled as 10 °C, 20 °C, 30 °C and so on.

12 By the time you have done this your thermometer should be showing room temperature on your scale. Mark this value on your paper.

13 Using a thermometer that has a scale marked on it, measure the temperature of the room. Compare this value with the value you obtained from your thermometer.

UN I T

H2 Making a scale of

temperature (page 2)

CHAPTER

WORKSHEET2

8

rubber bandsplain paper

rubber bandsplain paper

scale0 °C 100 °C

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UN I T

H3 Keeping it hotCHAPTER

WORKSHEET3

8


1 Wrap your insulation around a beaker. You may need to use a piece of sticky tape to hold it in place.

2 Pour some hot water into the beaker until it is about two-thirds full.3 Measure the temperature of the water and then immediately start your

stopwatch.4 Note the temperature of your water.5 Take the temperature of the water every half minute for 15 minutes.6 Note all your results in a table similar to this one:

7 Pour the water away, remove all the insulation and refill the beaker with fresh hot water.

8 Measure the temperature of the water. When it has reached the starting temperature of the water in the first part of the experiment, start your stopwatch. Measure the temperature of this water every half minute for 15 minutes.

9 Record all your results in the table.10 Using the information in your table draw two cooling curves, i.e. graphs

of temperature (y-axis) against time (x-axis).

1 Did your insulation reduce the rate at which the water lostenergy? Explain your answer.

2 What improvements could you make to your experiment tomake your insulation more efficient?

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Time in minutes Temperature of water Temperature of waterwith insulation ºC without insulation ºC

01/2

111/2

221/2

3etc.

thermometer

insulation

hot water

1 In pencil or chalk write the letter A on one side of the bimetallic strip andthe letter B on the other side.

2 Heat the strip with a hot Bunsen flame, keeping side A on top the wholetime. What happens to the bimetallic strip?

3 Take the strip out of the Bunsen and allow it to cool. What happens to thebimetallic strip?

4 Hold the strip again in the Bunsen flame, but this time keep side B on topthe whole time. What happens to the bimetallic strip?

5 Take the strip out of the Bunsen flame and allow it to cool.

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UN I T

H4 The bimetallic stripCHAPTER

WORKSHEET4

8


1 Which of the two metals expands the most when heated,metal A or metal B?

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A

B

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1 Cut out a square of silver foil measuring approximately 12 cm x 12 cm.2 Using a pencil or felt tip draw a spiral about 2 cm wide on the square.

3 Cut out the spiral using a pair of scissors.4 Using a sharp needle or pencil make a small hole in the centre of the spiral5 Thread a piece of cotton or thin string through the hole and tie a large

knot in the thread so that the spiral rests on it.6 Tie the free end of the thread to a glass rod.7 Hang the spiral over a small heat source such as a candle.

8 Watch what happens to the spiral. Can you explain what is happening?

H5 The spiral experimentCHAPTER

WORKSHEET5

8


1 There are several true stories of people who have parachutedfrom a plane but instead of falling gently downwards havefound themselves going up. Can you explain the strangeconditions that might have caused this to happen?

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12 cm

12 cm

glass rod

thread

silver foil

candle

1 The diagrams show the apparatus you aregoing to use.

2 You are going to put some purple crystals onthe bottom of the beaker and over to oneside. As these crystals slowly dissolve, theycolour the water so that you can see anymovement of the water. To start withoutcolouring the water, slide some very smallcrystals down a drinking straw.

3 Place a gentle heat source, e.g. a candle or alow Bunsen flame, directly beneath theposition where you placed the purplecrystals.

4 Look carefully at the movement of thewater as shown by the purple colouringfrom the crystals. Draw a diagram of theapparatus and add arrows to show howthe water in the beaker is being made tomove by the heat source.

5 Before the water becomes totally colouredby the crystals, move the heat source tothe opposite side of the beaker, so if youwere heating the left of the beaker at thebottom, move the heat source so it nowheats the right side. Has this affected themotions of the water? Draw a diagram toshow the movement of the water.

6 Using all the words and phrases below atleast once, write a full explanation of whatyou have discovered from this experiment:

more dense less dense warm water cools risesconvection current heat source sinks

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H6 Convection currents in

liquids8

CHAPTER

WORKSHEET6


purple crystals

coldwater

straw

gentle heatsource

tripod

The diagram below shows a house that has no insulation. Write in the boxeswhat kind of insulation you would use in the different parts of the houseand explain how this insulation would reduce heat loss.

325

H7 Insulating your home (page 1)

CHAPTER

WORKSHEET7

8


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H7 Insulating your home (page 2)

CHAPTER

WORKSHEET7

8


1 Which of these statements about the movement of heat aretrue and which are false?a Most of the hot air in a house will be upstairs.b Radiators give out most of their heat by radiation.c All metals are good conductors of heat.d Gases are good insulators because their particles are close

together.e Metal objects in a room are always colder than non-metal

objects because they are good conductors.f Convection currents can move heat energy through solids,

liquids and gases but not through a vacuum.g A wall made with a double thickness of brick is just as good

an insulator as a cavity wall.h The main insulating material inside glass fibre is not glass.

2 There are seven words associated with heat and heat transferhidden in this wordsearch. Can you find them all?

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I N S U L A T I O N

I R H C O L D T O E

H E A T C Q U I N E

O B P D L U T X R O

T R H A I C H B F C

H C M U U A F J L K

I W U D A J T P L I

K S N E B F H I S A

C O N V E C T I O N

C R D S D Y Y S G N

Your teacher is going to give you a boiling tube containing a substancecalled salol. Before the start of the lesson this substance was heated in awater bath to a temperature of about 95–100 °C. The liquid will still be veryhot when you collect it, so hold the top of the boiling tube and take greatcare not to spill any.

1 Stand the boiling tube upright. (Clamping it as shown above or putting itin a beaker will mean that you don’t have to hold it for the whole lesson!)

2 Measure the temperature of the salol using a thermometer. (Do this asquickly as possible after collecting it.)

3 Immediately you have done this, start your stopwatch.4 Without taking the thermometer out of the boiling tube measure the

temperature of the salol every half minute.5 Continue to do this until your teacher tells you to stop.6 While the salol is cooling, draw a results table like this one:

7 At the end of your experiment plot a graph of your results withtemperature on the y-axis and time on the x-axis.

8 Look carefully at the shape of your graph. Can you divide it into sectionsand say what is happening to the salol in these different parts?

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WORKSHEET8

8


Time (min) Temperature (ºC)01/2

111/2

221/2

331/2

4

thermometer

salol

retort stand


1 The mercury thermometer shown below is measuring the temperature of abeaker of water using the Celsius scale.

a What is the temperature of the water?

..............................................................................................................................

(2)b Name one other type of thermometer.

..............................................................................................................................

(1)

2 a A piece of meat is placed in a fridge. Explain why it gradually becomes colder.

..............................................................................................................................

..............................................................................................................................

(1)b Explain why when the same piece of meat is placed in a hot oven it

becomes warmer.

..............................................................................................................................

..............................................................................................................................

(1)

End of Unit test

Heating and cooling

CHAPTER

8

100 °C

80 °C

bulb of mercurybeaker of water

60 °C

40 °C

20 °C

0 °C

329

3 a Name a material that is a good thermal conductor.

..............................................................................................................................

(1)b Give one example of where this material is used because it is a good

thermal conductor.

..............................................................................................................................

(1)

4 a Name a material that is a good thermal insulator.

..............................................................................................................................

(1)b Give one example of where this material is used because it is a good

thermal insulator.

..............................................................................................................................

(1)

5 Jill has a stool which has metal legs and a plastic seat. The stool is at roomtemperature. When Jill touches the legs they feel cold but when she touchesthe seat it feels much warmer.a Explain why the legs feel cold.

..............................................................................................................................

..............................................................................................................................

(2)b Explain why the seat feels much warmer

..............................................................................................................................

..............................................................................................................................

(2)

6 Use particle theory to explain why conduction of heat through gases is muchmore difficult than conduction of heat through solids.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)




7 The diagram below shows a simple metal bridge.

a Explain why one end of the bridge is placed on rollers.

..............................................................................................................................

..............................................................................................................................

(2)b Explain what would happen if there were no rollers and no gap.

..............................................................................................................................

(1)

8 Why does air rise when it is warmed?

..............................................................................................................................

(1)

9 Suggest four ways in which you could reduce heat loss from a house.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(4)


expansion gap

end of bridge supported on rollers


10 The graph below shows how the temperature of a hot gas changes as it cools down.

a What is happening to the gas between the points marked A and B on the graph?

..............................................................................................................................

(1)b What is happening to this substance between the points marked C and D

on the graph?

..............................................................................................................................

(1)

Total marks: 25

Extension question

11 Using particle theory, explain what happens to a substancea when it meltsb when it boils.You may include diagrams with your answers if you wish.

(5)



Tem

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A B

C D


Text answers1 Our senses are unreliable. When we use them to try to measure

temperature they are influenced by previous conditions.2 Scale of temperature.3 The mercury in the bulb will contract and the height of the column will

decrease.4 The bread is cooler than the air in the oven so heat is flowing into the

bread making it hotter. The milk is warmer than the air in the fridge so heat is flowing from the milk into the surroundings. The milk therefore becomes colder.

5 a 37 °Cb 20 °Cc Out of your body. Heat naturally flows from warmer places to cooler

places.6 We want heat to flow easily and quickly from the hot water through the

radiator in order to warm the room. We want heat to flow easily from the flame through the base of the saucepan in order to warm/cook the food.

7 Since the handles of the saucepan and the spoon are made from materials that are good conductors, heat has flowed into them and they have become too hot to hold.

8 a The steel base allows a good flow of heat to the food.b The wooden or plastic handle prevents a good flow of heat so the

handle remains cool enough to hold.9 a The Bunsen flame warms all the inner ends of the bars equally. This

energy travels by conduction to the cooler outer ends. When they become sufficiently hot the wax melts and the marbles fall from the bars.

b The first marble to fall will be attached to the bar that is the best conductor.

10 ‘My head and feet feel as though they are the same temperature.’11 They trap more air by fluffing up their feathers, i.e. they are even better

insulated.12 a The particles on the side of the solid being heated gain energy and

vibrate more vigorously. These ‘hot’ particles jostle their neighbours, causing them to vibrate more. This continues through the solid, i.e. heat is flowing through the solid.

b The particles in a gas are much further apart than they are in a solid and so it is much more difficult to ‘pass on the extra vibrations’ to neighbouring particles.

13 Tar or bitumen. As the temperature rises the tar becomes soft. It is then easily squeezed out of the way by the expanding concrete sections.

14 a Bridges (expansion gap and rollers), telephone wires (allowance must be made for changes in length as temperature changes), roads built in sections (expansion gaps and tar), etc.

b Riveting, thermometers (e.g. mercury in glass), bimetallic strip.15 Liquid-in-glass (or mercury-in-glass) thermometer.16 If the petrol becomes warm while inside the tank it will expand and

overflow.17 a At the top because the hottest water will be the least dense and so rise

to the top.

Heating and coolingC

HAPTER

8

ANSWERS


b At the bottom because the coldest water will be the most dense and so sink to the bottom of the cup.

18 The particles in a solid are held in fixed positions.19 Particles are needed to transfer heat by conduction or convection.

Transfer of heat by radiation can occur without particles. There are no particles between the Earth and the Sun so heat transfer between the two must be by radiation.

20 A double-glazed window consists of two sheets of glass with a narrow layer of trapped air between them. Cavity walls consists of two walls with a layer of air trapped between them.

21 a A solid is melting when it is changing into a liquid. A liquid is freezing when it is changing into a solid.

b The temperature at which a substance changes from a solid to a liquid.22 CD – The energy given to the liquid causes its particles to move around

more quickly. DE – When the particles have gained enough energy, they are able to escape the attractive forces of their neighbours. EF – The particles gain more energy and move around at higher speeds as the temperature increases.


a exception one that does not fit the patternangular shape not smooth, having parts that stick out in different

directionsunique exceptional, only one of a kindcrucial very important, vitalinhibits reduces, restricts, slows downarctic conditions very cold conditionsaquatic life plants and animals that live in/under water

b Water molecules cannot pack close together because they have angularshapes.

c Ice.d If water started to freeze at the bottom of lakes and ponds the process

would continue until all the water had frozen. Most, if not all, life forms inthe water/ice would therefore die. It is thought that life on Earth started inwater. If this could not survive there would be no life forms.


1 a freezingb radiationc convection currentd insulatione conduction

2 a Plastic, wood; an insulator is need to prevent or reduce heat transferb Steel; a strong material which is a good conductor is neededc Wool, fleece; a light, insulating material is neededd Air; an insulating, transparent material is needede Steel, copper; an excellent conductor is needed to allow good heat

transfer to the food

3 a Stale air removed from the mine and replaced with fresh air.b Without ventilation the amount of oxygen in the air would decrease and

miners would eventually die.

Chapter 8 Answers


c Air above the fire became warm, less dense and so rose up the mineshaft. Fresh, cooler, more dense air entered the second mineshaft and travelled along the mine workings to the fire.

d There was always the danger that gases released by the mining might explode if they came in contact with the fire.

4 a It is not possible to unscrew the cap.b The cap becomes warm and expands (far more than the glass). As a result

it becomes loose and easier to unscrew.

5 a The jar will crack.b When the boiling water is poured, the inside of the jar will become very

hot and expand. Glass is not a good conductor of heat so the outside of the jar will not become hot and expand. The stresses created by this difference in behaviour will cause the glass (which is a brittle material) to crack.

6 a, b

c 110 to 100 °C: the particles in the vapour are losing energy and their movements are slowing.

100 °C: the particles are being pulled closer together to form a liquid.

100 to 0 °C: the particles in the liquid are losing energy and their movements are slowing.

0 °C: the particles are moving so slowly that the forces of attraction between them are beginning to hold them in fixed positions.

0 to –10 °C: the vibrations of the particles in their fixed positions becomes less vigorous.

7 a 20 °C b 0 °C c 100 °Cd –90 °C e 60 °C f 37 °Cg 200 °C h 1100 °C i 6000 °Cj 15 000 000 °C

Chapter 8 Answers

110 °C

100 °C

90 °C

80 °C

70 °C60 °C

50 °C

40 °C

30 °C

20 °C10 °C

0 °C–10 °C

Time

Tem

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atu

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water vapour condensing

water cooling

water freezing

ice cooling

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Worksheet answers

H1 How hot is it?Step 7 Each hand is comparing the temperatures of the two bowls they havebeen in. The hand that was first in the hot water will now feel cold in thelukewarm water. The hand that was first in the cold water will now feel muchwarmer when placed in the lukewarm water.1 Our senses are unreliable. When we use them to try to measure temperature

they are influenced by previous conditions.2 Possible answers include (a) clinical thermometer, (b) an alcohol in glass

thermometer.

H3 Keeping it hot1 It should have done! Insulation will reduce the rate heat is lost from the

water.2 Possible improvements include greater thickness of insulation, insulated lid

for beaker, keeping trapped air to a maximum by not squeezing theinsulation, different material for insulation, e.g. one containing moretrapped air.

H4 The bimetallic strip1 The metal that expands the most will be on the outside of the bend when

the strip is heated.

H5 The spiral experiment1 The ground has become so very hot that the density of the air above it has

been greatly reduced. As a result this air rises quickly (called a thermal). Ifthe thermal is strong enough it can carry objects, e.g. parachutists, upwards.Although thermals are not uncommon, ones that are strong enough to dothis are quite rare.

H6 Convection currents in liquidsStep 6 A possible answer is: The heat source will warm the water directlyabove it. This warm water will be less dense than the cooler water around itand so rises. Away from the heat source the water cools, becomes more denseand so sinks. This circular motion of the water driven by the heat source iscalled a convection current.


Chapter 8 Answers

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H7 Insulating your home

1 a True b False c Trued False e False f Falseg False h True

2 Insulation, radiation, hot, heat, cold, convection, conduction


1 a 40 (1) ºC (1)b Any other thermometer, e.g. thermocouple, thermochromic tape (1)

2 a Heat (energy) flows out of the meat (1)b Heat (energy) flows into the meat (1)

3 a Any metal (1)b Any relevant example, e.g. base of saucepan, radiator (1)

4 a Any plastic, any material with trapped air, accept air (1)b Table mat, clothing, double glazing, etc. (1)

5 a The metal leg is a good conductor (1) so heat escapes quickly from Jill’s body/hand (1)

b The plastic seat is not a good conductor (1) so heat does not escape quickly from Jill’s body/hand (1)

6 The particles in a gas are much further apart than the particles in a solid. (1) It is therefore more difficult for gas particles to pass on vibrations to their neighbours (1)

7 a When the bridge becomes warmer/colder it expands/contracts. (1) The rollers allow this change in length to happen without damaging the bridge. (1)

b The bridge would be damaged, e.g. buckle or crack (1)8 It is less dense than the (cooler) air around it (1)9 Any four from: install loft insulation, fit double glazing, fit carpets or

underlay, fit draft excluders, install cavity wall insulation, fit thick curtains (4)


Chapter 8 Answers

Loft insulation such as fibreglass reduces heat loss through the roof.

Double glazing and thick curtains reduces heat loss through windows.

Cavity walls and cavity wall insulation reduces heat loss through walls

Fitting draft excluders and filling in gaps and cracks reduces heat loss from the house.

Fitted carpets and underlay reduces heat loss through floors.

layer of air

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gap between walls

outer wallinner wall

337

10 The gas is changing into a liquid (accept condensing) (1)The liquid is changing into a solid (accept freezing) (1)

Total marks: 25

Extension answers

11 a If we heat a solid the particles from which it is made will vibrate more vigorously. Eventually if we continue to heat the solid the particles gain enough energy to overcome the forces holding them in their fixed positions and they are now able to move about and flow past each other. The solid has melted. (3)

b If we heat a liquid, eventually all its particles will gain enough energy to become completely free from any attractive forces and are able to move around at high speeds. The liquid has boiled. It has changed into a gas. (2)



Chapter 8 Answers


Pupils should be familiar with the following ideas:• There are rocks under the surface of the Earth and soils come from rocks• Some examples and uses of rocks• Solids, liquids and gases are made of particles; the differences between the way

particles are arranged in solids and liquids• Know how to determine the pH of a solution and how this relates to acidity

and alkalinity• Dissolved solids are left behind when water evaporates

9 Rocks and weathering

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QC

A S

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Un

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G

Starting points


Calcium carbonateChalkClayDepositionDisintegrateErosionFeldspar

Flood plainFossilGrainsGraniteLimestoneMicaMinerals

MudstoneQuartzRock saltSandSandstoneSedimentSedimentary rocks

SiltSiltstoneStrataTransportWeathering

In this topic pupils should learn:• about rock texture as one of the key characteristics of different rock types• to model rock texture• about the processes of weathering, erosion, transportation and sedimentation• to relate processes, e.g. evaporation and dissolving, involved in rock formation to

processes observed in other contexts• to consider processes operating on different timescales• to consider how evidence from sedimentary layers and from fossils has led to

changes in ideas about the development of the Earth• to make qualitative observations, including use of time-lapse photography to

record gradual changes, evaluating methods used• to frame questions to be investigated and to present data in an appropriate way• to use scientific knowledge and understanding to explain observations• to investigate a question about sedimentation

Learning checklist

Links

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Unit Title3D Rocks and Soils


CH A P T E R

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Cross-curricular linksGeography: unit 2 ‘The restless earth – earthquakes and volcanoes’, unit 7 ‘Rivers– a fieldwork approach’ and unit 8 ‘Coastal environments’.

LiteracyThere is a literacy activity on Mary Anning in the Pupil Book.

ICTPupils will use ICT to make and record observations and explain these usingscientific knowledge and understanding.


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Scientific enquiry• Describe evidence for a sequence of geological events• Suggest a question to be investigated about the movement of sediment and,

with help, identify an appropriate approach• Use ICT to make and record observations and explain these using scientific

knowledge and understandingMaterials and their properties• Describe rock specimens in terms of texture and relate this to properties such as

porosity• Describe the physical and chemical processes by which rocks are weathered and

transported and relate these to features of the environment• Describe and explain the processes by which layers of sediments are produced

Pupils who have not made so much progressScientific enquiry• Describe changes in rocks or rock fragments over time• With help, identify a question about movement of sediment to be investigated

and use ICT to make and record observations related to the questionMaterials and their properties• Describe rock specimens and recognise that different rocks have different

textures• Describe some effects of weathering and recognise sedimentary layers

Pupils who have progressed furtherScientific enquiry• Use evidence from several sources to describe a sequence of geological eventsMaterials and their properties• Relate processes of chemical weathering to the reactions of particular grains

with acids• Relate sedimentary layers to the processes by which they were produced

Learning outcomes



Unit Title7E Acids and Alkalis7H Solutions8F Compounds and Mixtures8H The Rock Cycle8I Heating and Cooling

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The topic is introduced by ensuring that pupils understand that rocks are alwayspresent underground. You could show them samples of the local rock types toreinforce this idea.

It is suggested that you use the term ‘grains’ to describe the small pieces thatrocks are made of. ‘Particles’ is best avoided, as pupils use this term for atoms,molecules and ions.

WeatheringWorksheet I1, What are rocks are made of?, asks pupils to look very closely atsamples of different types of rock. This activity will help them to understand howrocks can be broken into fragments or grains by weathering processes. The tableon the worksheet lists only three rocks – granite, sandstone and limestone – butyou could extend this to include other types as well. Try to include a relativelyporous rock (which releases air bubbles when submerged in water) and also yourlocal rocks. You could also use this activity to introduce the term ‘mineral’ for thechemicals that make up rocks. For example, it is usually easy to see that granite ismade up of at least three different kinds of minerals.

The third photograph on page 127 in the Pupil Book can be used to introducethe idea that rocks are not permanent fixtures, and to take a first look at the ideaof weathering – the weakening and subsequent disintegration of rock. You couldshow pupils pieces of well-weathered and unweathered rocks. Local buildingstones may be suitable for this; surfaces which have been exposed to the air formany years will show weathering, and you can compare this with a freshlyexposed surface of the same rock (perhaps by splitting open a building stone).

Worksheet I2, How does rain cause weathering of rocks?, and Worksheet I3, Howdo temperature changes cause weathering of rocks?, look at some of the many waysthat weathering can take place. You could introduce Worksheet I2 by showingpupils a piece of limestone and asking if anyone can remember what limestone ismade of. (This was mentioned in Year 7 Book 1 Chapter 6, in connection with theaction of acids on carbonates.) Pupils can also be prompted to recall what theyknow about the production of acid rain (Year 7 Book 1 Chapter 3) and how acidsreact with carbonates (Year 7 Book 1 Chapter 6). Ask them to predict what mighthappen when hydrochloric acid comes into contact with limestone, before askingthem to carry out the first activity on Worksheet I2.

The second activity, involving chemical weathering of granite, is best done as ademonstration. It is strongly recommended that you try this out for yourself on atleast two different types of granite, before carrying the demonstration out for theclass. You want to be able to see clear differences in the effect of the acidicsolution on different minerals in the rock. The use of a digital camera to recordthese changes over time would be ideal, especially if you can display a magnifiedimage of the rock surface on a screen so that the whole class can see it at once.

Worksheet I3 could be introduced by asking pupils to use their knowledge ofheating and cooling (Chapter 8) to predict what will happen to a piece of rockwhen it is heated, and when it is cools down again. You can use this asopportunity to help them to revise their understanding of expansion on heatingin terms of the particle model. Take care, though, that they do not equate‘particles’ (atoms, molecules) with the ‘grains’ that they have seen rocks to bemade up of.

Eye protection should be worn when heating rocks.


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The strange behaviour of water – expanding when it freezes – could just bepresented as a fact. However, if pupils show an interest in why this happens, youmight like to explain it in terms of what the particles (water molecules) are doing.When water freezes, the particles settle in a lattice arrangement where they arefurther apart than when in very cold liquid water. It is important that pupilsunderstand that it is repeated freeze–thaw cycles that can cause breakdown of rock.So this type of weathering is much less important for rocks in permanently coldplaces than in ones where temperatures during winter oscillate on either side of 0 °C, such as in mountains in Scotland.

What happens to the rock fragments?This section of the Pupil Book describes erosion, transport and deposition of therock fragments that are produced by weathering. Take care that pupils understandthe distinction between weathering and erosion. Weathering can be defined as thedisintegration of rock in situ, while erosion is the removal of the rock fragmentsfrom the site. The Pupil Book and worksheets concentrate on water as the agent oferosion, but you may also like to mention wind, glaciers and gravity, especially ifyou are going to take pupils out of doors to look at areas where these have beenimportant factors in the formation of the landscape.

Information about the names for the different sizes of rock fragments is provided atthis point, but this could equally well be dealt with earlier, in connection withweathering. The diagram on page 131 in the Pupil Book reinforces this idea, andalso reminds pupils that some substances are carried in solution. Question 2 onpage 131 looks at this idea, helping to prepare pupils for thinking about howevaporation can lead to rock formation, covered later in this chapter.

The transport of rock fragments by rivers is described in terms of the energy of thewater – the faster the water is flowing, the larger (heavier) the rock fragments thatit can carry. When the water slows and its energy drops, the larger fragments aredropped or deposited. Things are not really quite that straightforward – the volumeof water that is flowing is also important – but it is probably best to keep thingsfairly simple at this stage. Pupils will have seen film of rivers in flood, and youcould show video clips of such events.

Worksheet I4, Investigating the transport of rock fragments by rivers, provides anopportunity for pupils to see for themselves that there is a relationship betweenspeed of flow and the ‘river’s’ ability to carry sand grains. They are asked first touse a dye to help them to see where the water is flowing most quickly (where therubber tubing drops water onto the sand, and then in the centre of the gutter) andmost slowly (along the sides and bottom, and in the ‘pool’ at the lower end) andthen to relate this to their observations of the erosion, transport and deposition ofthe sand grains. You could extend this investigation in many ways, for example byusing a mix of gravel and pebbles of different sizes instead of sand, or by varyingthe slope of the gutter.

Take care to trap any escaping sand grains in a large beaker or other container, sothat they do not block the sink. Whatever you do, water will inevitably end up onthe floor, so make sure that pupils are aware of this as it is a potential safety hazardif the floor becomes slippery.

It is best to do this activity as a demonstration, but you may not be able to get allpupils around the gutter at the same time. If you can call on another member ofstaff to help out, then you could run two demonstrations simultaneously. Anotheroption is to show half the class this demonstration while the other half is doingsomething else.



Worksheet I5, How does a river change the shape and size of rock fragments?, looksat how energetic movement of rock fragments causes them to knock against eachother, changing their shapes and reducing their size. This could be done as apurely qualitative exercise – pupils just see that the rock pieces become morerounded and smaller – or, as described in the worksheet, it can be madequantitative by finding the mass of the rock pieces. A difficulty here is decidingwhich pieces to mass and which to ignore. One way of doing this would be topour the contents of the pot into a sieve, discarding the small grains that fallthrough and finding the mass of what is left. Pupils are left to decide forthemselves how best to display their results. If they have managed to measure themass of the remaining fragments at least four or five times, then they could drawline graphs of total mass of fragments (y-axis) against number of shaking cycles. Ifthey have data for more than one type of rock, where the initial masses weredifferent, then ideally they should calculate percentage change in mass for eachtype of rock and plot that. This, however, is quite a difficult task to understandand to carry out, which perhaps you might expect only of the more able pupils.

The worksheet describes this activity using pieces of real rocks. If you cannotsupply these (or cannot afford to have them tested to destruction), the activity canbe carried out with cubes made from plaster of Paris. These also have theadvantage that they disintegrate relatively quickly. Alternatively, you could usereal rocks but carry out the activity as a demonstration. Whichever method youchoose, be warned that this is an extremely noisy investigation. You can keepthings under some degree of control by ensuring that all pupils do their shaking atthe same time.

An alternative investigation here would be to put three or four different types ofrock in the container together, and compare the rate at which each type losesmass when they are shaken together. This is a more realistic representation ofwhat really happens in rivers.

Sedimentary rocksHaving described weathering, erosion and transport, the Pupil Book now looks alittle more closely at deposition, and the subsequent formation of sedimentaryrocks from deposited material.

Most pupils will be aware that when a flooded river subsides, it leaves behindmud and other material that it had been carrying. Help pupils to use theirunderstanding of the relationship between water speed and ability to carryfragments of different sizes to understand why rock fragments of similar sizes tendto be deposited together. Thus, rocks are often formed that are made up of similarsizes of particles.

The Pupil Book explains that, over long periods of time, thick layers of sedimentcan build up, which eventually become rocks. As more and more layers build up,their weight compacts the layers below. Where the particles are very small (forexample clay particles), this may be enough to form a relatively solid rock, butwith larger particles such as sand grains some type of ‘cement’ must infiltratebetween them in order to fix them together.

The conversion of deposited sand grains into rocks is investigated in WorksheetI6, Making sandstone. To compare how strong a rock is, you could suggest standingmasses on top of the rock to find the maximum weight that it can support beforeit breaks, squashes or crumbles.

EvaporationSedimentary rocks are, of course, formed in other ways than the deposition of


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rock fragments transported by rivers. The section on evaporation could beintroduced by using question and answer to help pupils to remember what theyknow about the Dead Sea, and how evaporation is used to obtain deposits ofchemicals which are subsequently collected for use as fertilisers (Year 7 Book 1Chapter 9). They may also remember about the formation of rock salt. Theycould then be helped to predict what would happen if all the water in a lakeevaporated.

The formation of limestone and chalk, and of fossils, brings living organisms intothe picture for the first time. Pupils may like to know that the Sphinx, as well asmany other structures humans have built from limestone, is actually made up ofthe shells of billions of tiny marine organisms.

Pupils are now in a position to understand that rocks may be stacked on top ofeach other in layers, called strata, with the oldest ones at the bottom of the stackand the youngest ones on top. Looking at the strata can help to tell the story ofthe geological history of that area. The enormous time scales that are ofteninvolved are very difficult to comprehend. You could take this further at this point– for example by explaining that sharp boundaries between layers indicate thatthere was a time interval between their formation – but as pupils have not yetbeen asked to look at how landscapes are affected by weathering this is probablya step too far at this stage. Worksheet I7 asks pupils to use evidence from stratato tell a simple geological story. You could extend this by asking pupils to makeup a geological story, and then ask other pupils to draw the rock sequence thatmight have been formed.

Literacy activityThe Literacy activity on Mary Anning is a very brief summary of her famousstory. There is a wealth of material about her life in various publications and onthe internet, if you would like to take this further. If time allows, you could askone or two pupils to read the account in the Pupil Book aloud, and then discusswith them the meanings of any words that are unfamiliar to some of them – forexample ‘vital’, ‘curios’, ‘geologist’, ‘aggrieved’. Question 1 asks pupils to writean imaginary dialogue – you could help them by discussing how the twoprotagonists might act, for example how Mary might describe her new-foundfossil and how she might try to elicit a good fee from the geologist; and howexcited he might be to hear about it, asking Mary lots of questions that shecannot answer.

This topic could easily be developed further to illustrate some of the ideascovered in this chapter, by researching information about the different rock layerspresent in the cliffs around Lyme Regis, thinking about how they were formedand why they contain fossils, and what the fossil sequence tells us about how thetypes and numbers of species in the seas changed over a period of millions ofyears. Again, the internet – and also leaflets aimed at tourists to the Lyme Regisarea – will provide a wealth of material on this topic.



Sc1

Scientific Enquiry

1b, 2a, 2g, 2m

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Physical Processes

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What I have learnt

Rocks and weathering


Calcium carbonate

Chalk

Weathering

Sandstone

Clay

Mudstone

Deposition

Flood plain

Grains

Fossil

Sedimentary rocks

Granite

Rock salt

Mica

Quartz

Transport

Sand

Minerals

Limestone

Sediment

Siltstone

Erosion

Feldspar

Strata

Silt

Disintegrate


• I know that there are rockseverywhere under the surface ofthe Earth and that rocks are madeup of grains of different chemicals

• I know that rock texture is one ofthe main characteristics of differentrock types

• I know about weathering, erosion,transportation and sedimentation

• I know that weathering is theweakening and breakdown of rocks

• I know that rain can causeweathering, especially if it containsacid

• I know that heating and coolingcan cause weathering

• I know that erosion is the removalof rock fragments from where theywere formed

• I know that rivers erode, transportand deposit rock fragments

• I know that deposited rockfragments can be compressed andcemented so that they becomesedimentary rocks

• I know that sedimentary rocks canalso be formed from the remains oftiny organisms, and by evaporation

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on this topic

CHECKLIST

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Lesson Focus Pupil Book 2 p. 127Introduction to rock structure

ExpectationsMost Pupils Know that rocks are made of grains. Know that some rocks contain

different kinds of grains. Recognise at least three different kinds ofrock samples.

Less Able Pupils Know that rocks are made of grains. Identify at least two differentkinds of rock samples.

More Able Pupils All the above, plus use observation to work out the relationshipbetween the degree of interlocking between grains and porosity.



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Worksheet I1 What are rocks madeof?Several samples of different types ofrocks, labelled with their names, toinclude limestone, granite and sandstone,distributed around the roomHand lensesContainers of water into which rocksamples can be immersed

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10 In and register. Pupils revise their knowledge that there are rocks under the Starter. Use Q and A to ask pupils ‘What are rocks?’, ‘Where are rocks found?’ surface of the Earth. They begin to consider that rocks may Use photographs on page 127 of the Pupil Book to ensure pupils understand that disintegrate.rocks are present under the surface of the Earth. Introduce the idea that when rocks are exposed, they may start to break down.

25 Development. With pupils, look through and discuss Worksheet I1 What are Less able pupils will need help to complete Pupils see that rocks are made of grains. They describe rocks made of? Ask pupils to complete this worksheet, using samples of rocks at least the first row of the table. rock specimens in terms of texture and other properties. distributed around the room. More able pupils will give more detailed They relate the observable structure of the rock to its

descriptions, and may describe more rock samples porosity.in the time available.

10 Plenary. Settle pupils. Discuss their results with them. Use Q and A to draw out Less able pupils will use this session to complete Pupils consolidate their understanding that rocks are made of the observations that all the rocks are made of ‘bits’ and introduce the word descriptions for at least three rock samples. More a mixture of different grains. They have a written description ‘grains’ to describe these; that some rocks contain more than one kind of grain; able pupils will realise that the more tightly the of the appearance of at least three different types of rock.that different kinds of rocks contain different sizes of grains. Use Q and A to grains are interlocked, the less porous the rock.elicit the relationship between the degree to which grains interlock and porosity. Ensure that all pupils have enough information to be able to write at least a brief description in each box in their results table.

5 Use Q and A to help pupils to recall what they know about the effects of acids More able pupils will recall this reaction. Pupils revisit the action of acids on carbonates.on carbonates.

Homework: (a) Use the results table from Worksheet I1 to write a brief description that would help someone to identify granite, sandstone and limestone rocks. (b) Predict what might happen to a piece of limestone if acid rain fell on it.


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Lesson Focus Pupil Book 2 pp. 128–129Weathering of limestone and granite by water

ExpectationsMost Pupils Know the meaning of the term ‘weathering’. Understand the effect

of acid rain on limestone. Know that granite contains grains ofthree different minerals.

Less Able Pupils Know that acid rain can cause limestone to break down. Know thatgranite contains three different kinds of grains.

More Able Pupils All the above, plus understand the effect of acid rain on limestonein relation to the action of acids on carbonates. Identify and namethree minerals found in granite.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy:ICT: Use of digital camera to produce time-lapse sequence.


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Worksheet I2 How does rain causeweathering of rocks?Per group:Small piece of limestone or chalkSmall bottle of 0.5 mol dm–3 hydrochloricacid, with dropperGoggles

Demo: Chemical weathering of graniteSmall pieces of granite with clearly visiblegrains of feldspar, mica and quartzBeaker containing 0.5 mol dm–3

hydrochloric acid and 10 volumehydrogen peroxide, in equal volumes(sufficient to cover a piece of granite)Beaker containing waterDigital camera and/or video cameraattached to binocular microscope ifavailable

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5 In and register. More able pupils will remember earlier work on Pupils recall knowledge of acid rain, and of the action of acids Starter. Ask pupils for their predictions about what might happen to a limestone acid rain, and the action of acids on carbonates, on carbonates.rock when acid rain falls onto it. Ask: What causes acid rain? and will volunteer information.

10 Development. Distribute Worksheet I2 How does rain cause weathering Pupils see the effect of acid on limestone.of rocks? Ask pupils to carry out the first activity, Acid rain and limestone.Safety! Acid is corrosive – remind of care needed, and ensure goggles are worn.

10 Bring pupils to the demonstration bench and settle. Use Q and A to draw out More able pupils will be quicker to link previous Pupils link their understanding of acid rain and the action of descriptions and explanations of what happened when acid was dropped onto knowledge with their observations in this activity. acids on carbonates to the weathering of limestone. They are limestone. Ask: Might this happen to limestone rocks out of doors? What effect introduced to the term ‘weathering’.might it have on them? Link this to the use of the term ‘weathering’. Look at photographs of weathered limestone, for example the photograph on page 128 of the Pupil Book, and discuss what has caused this.

10 Hand round samples of granite. Ask pupils to look again at the grains from which Pupils are introduced to the term ‘mineral’ and learn the it is made, and help them to identify the different minerals, using the photograph names of three minerals found in granite rocks.on page 129 of the Pupil Book. Set up the demonstration of Acid rain and granite.

10 Ask pupils to write up their investigation of the effects of acid rain on limestone Pupils have a record of the action of acid rain on limestone.in their workbooks.

5 Plenary. Ask pupils: What does the term ‘weathering’ mean? Can they think of Less able pupils will need help to progress from a Pupils build on their first use of the term ‘weathering’ to think any other ways that rocks might be damaged/weathered? Set homework. specific instance of weathering to a more general about its application in wider contexts.

use of this term.

Homework: Predict and explain what might happen to a rock if it is repeatedly heated and cooled, and explain the prediction using knowledge of how particles behave.


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Lesson Focus Pupil Book 2 pp. 129–130Weathering of rocks as a result of temperature changes

ExpectationsMost Pupils Understand that repeated heating and cooling causes expansion

and contraction of rock, which can make it break. Know that this isa type of weathering.

Less Able Pupils Know that heating and cooling rock can make it break.

More Able Pupils All the above, plus be able to describe the effect of repeatedheating and cooling on rocks in terms of particle theory.



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Worksheet I3 How do temperaturechanges cause weathering of rocks?Demo: Heating and cooling rocksGranite chips 7–10 mm acrossBunsen burnerBlowpipeTongsLarge beaker of cold waterGogglesSafety screen

Per group:Small plastic bottleTwo small pieces each of unweatheredgranite and limestoneTwo plastic containers large enough tohold two rock pieces immersed in waterMeans of labelling containersAccess to freezerDigital camera or video camera attachedto binocular microscope if available

Demo: Chemical weathering of graniteGranite in acid and H2O2 from last lessonTongsDigital camera or video camera as before

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10 In and register. More able pupils should link their understanding Pupils recall knowledge and understanding of the expansion of Starter. Ask pupils: What do you predict will happen to a rock when it is of particle theory, and knowledge of expansion of solids when heated, and apply this to the effect of repeatedly heated and cooled? Why will this happen? solids on heating, and be able to predict the temperature changes on rocks.

effect of heating and cooling on rock.

10 Development. Bring pupils to demonstration bench. Distribute Worksheet I3 Pupils see the effect of heating and cooling on granite.How do temperature changes cause weathering of rocks? Demonstrate and discuss the Heating and cooling activity.Safety! Rock piece may shatter, so use a safety screen and ask pupils to wear goggles.

10 Ask pupils to write up a description and explanation of this activity in their Less able pupils will require help, especially with Pupils have a record of the effect of heating and cooling on a workbooks. the explanation. piece of granite, and reinforce their understanding of why this

happens.

10 Talk through the Freezing and thawing activity on Worksheet I3. Ask pupils to carry out steps 1 and 2.

10 Bring pupils to the demonstration bench once more, and show them the granite Pupils begin to look for, and see, the effects of ‘acid rain’ on from Worksheet I2. Compare this with a piece of untreated granite, and discuss granite.any changes that can be seen. Set homework.

Homework: Write up the method of steps 1 and 2 of Freezing and thawing in workbooks. Leave space for the results of Heating and cooling.


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Lesson Focus Pupil Book 2 pp. 128–130Drawing together results and explanations of different kinds of weathering

ExpectationsMost Pupils Know that repeated freezing and thawing can cause rocks to

shatter, and relate this to knowledge that water expands when itfreezes. Know that weathering can affect different minerals indifferent ways.

Less Able Pupils Know that freezing can cause rocks to shatter because waterexpands when it freezes.

More Able Pupils All the above, plus be able to explain the effect of repeatedfreezing and thawing in terms of particle theory. Describe thedifferent effects of ‘acid rain’ on feldspar, mica and quartz.



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Spare copies of Worksheet I3 How dotemperature changes causeweathering of rocks?Water bottles and rock samples from lastlesson


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10 In and register. More able pupils will question why water expands Pupils know that water expands when it freezes. They begin to Starter. Ask pupils to collect their bottles of water from the freezer. Settle them, when it freezes and will be offered an explanation think about how this might affect rocks.and ask: What has happened to the water? If water got into cracks in rocks and in terms of particle theory.then froze, what might happen?

10 Development. Ask pupils to collect their frozen and thawed rock samples from Pupils see that freezing and thawing can make rocks crack Worksheet I3 How can temperature change cause weathering of rocks?, apart. They relate this to their observation that water expands and also their untreated samples. Settle them, and ask: Can you see any when it freezes.differences between them? If so, can you suggest an explanation for these differences? Ask them to replace the frozen and thawed samples in the freezer.

10 Ask pupils to write up their results from the Freezing and thawing activity from Less able pupils will need help to answer the Pupils have a record of the effect of freezing and thawing on Worksheet I3, including answers to the questions. (If results are not yet obvious, questions fully. rocks, and consolidate their understanding of why this postpone this to next lesson.) happens.

10 Remind pupils of the Acid rain and granite activity on Worksheet I2. Remove the More able pupils may be quicker to see that some Pupils appreciate that, in rocks made of different minerals, piece of granite from its solution, rinse and dry it. Use a video camera to project minerals are affected more than others, and be some may be affected by weathering more than others.an image of the surface of the granite onto a screen. Compare its appearance able to name those that are most affected.with that of an untreated piece of granite. Are there any differences between them? If so, discuss the reasons for the differences.

10 Plenary. With the class, list the different types of weathering they have Pupils acquire an overview of what weathering is and some investigated. Use Q and A to check pupils understand what weathering is, and examples of how it occurs.how acid rain, heating and cooling, freezing and thawing can cause weathering. Set homework.



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Lesson Focus Pupil Book 2 pp. 130–131Introduction to erosionThe erosion, transport and deposition of rock fragments by flowing water

ExpectationsMost Pupils Know that erosion is the removal of rock fragments, which have

been produced by weathering. Know that flowing water can erode,transport and deposit rock fragments. Know that the faster thewater flows the bigger the fragments it can carry.

Less Able Pupils Know that flowing water can carry away and deposit rockfragments. Know that the faster the water flows the bigger thefragments it can carry.

More Able Pupils All the above, plus use the terms weathering, erosion, transportand deposition correctly and with confidence. Understand whyfragments of similar sizes tend to be deposited together.



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Stimulus material to introduce erosion,e.g. photographs or video clips of riversin flood

Worksheet I4 Investigating thetransport of rock fragments by riversDemo: Transport of rock fragments1 m length of square section gutteringwith two end piecesClean sand to fill guttering to within 2 cmof the top of gutteringRubber tubing to connect to water tapClip to hold tube in placeLarge container to place in sink to catchsand particlesSmall quantity of coloured dye, e.g. blueinkGravel or pebbles

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10 In and register. Pupils consolidate their knowledge of the effect of acid rain on Review the Acid rain and granite activity, and look at the granite surface as granite.before. Discuss any changes and the reasons for them.

5 Starter. Ask pupils: When rocks have been broken apart by weathering, what Pupils consolidate their understanding of the term might happen to the pieces? Show photographs and video clips if available, of ‘weathering’ and are introduced to the term ‘erosion’.erosion processes taking place. Explain the meaning of the term ‘erosion’.

25 Development. Distribute Worksheet I4 Investigating the transport of rock Less able pupils may have difficulty in picking Pupils see that flowing water can erode, transport and fragments by rivers. Settle pupils around the apparatus, and pose the first out relevant observations from what they see, deposit sand and gravel particles. They relate erosion and question. Demonstrate the first part of the activity, asking pupils to make notes. and will need help with this. deposition of particles to their size and to the speed of Pose the second question, and demonstrate this part of the activity. If time, water flow.pose a third question: Does the size of the rock fragments make any difference? Pupils are introduced to the terms ‘transport’ and Repeat the second part using gravel instead of, or as well as, sand. ‘deposition’.

10 Plenary. Settle pupils. Talk through the findings of the investigation with them. Less able pupils will require help to answer the Pupils clarify their understanding of the relationship between Check that each pupil has sufficient notes to enable them to do the homework. questions on the worksheet. They can be provided speed of water flow and the size of particles that are Set homework. with an outline diagram of the guttering with transported or deposited.

partially completed labels, if required.

Homework: Write an account of the findings and answers to the two questions on Worksheet I4.


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Lesson Focus Pupil Book 2 pp. 131–132Loss of mass and change in shape of rock fragments transported by a river

ExpectationsMost Pupils Know that rock fragments become smaller and more rounded as

they are transported in moving water. Identify an appropriate wayof measuring and recording results. Choose a suitable method ofdisplaying results to enable comparisons to be made.

Less Able Pupils Know that rock fragments become smaller and more rounded asthey are transported in moving water. With help, use appropriatemethods of measuring, recording and displaying results.

More Able Pupils All the above, plus suggest and justify appropriate methods ofmeasuring, recording and displaying results.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Calculating percentage changes in mass; plotting data as line graphs.ICT:


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Worksheet I5 How does a river changethe shape and size of rock fragments?Per group:Four expendable pieces, each about 50 g,of at least one type of relatively ‘crumbly’rock, e.g. sandstone, limestoneIf possible a second type of rock, e.g.graniteStrong plastic container with wide topand tightly fitting lid in which one set ofrock pieces can be shaken aroundAccess to top pan balanceSieves of different mesh sizes

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10 In and register. More able pupils are likely to be quicker to predict Pupils consolidate their understanding that flowing water can Starter. With pupils, review the activity from last lesson, and discuss the that rock fragments transported in water may be erode, transport and deposit rock fragments.relationship between speed of flow and size of rock fragments carried. damaged by contact with each other.Ask pupils: Imagine a river rushing along carrying rock fragments – what might happen to them as they are carried along?

20 Development. Distribute Worksheet I5 How does a river change the shape Less able pupils will need help in deciding Pupils see how transported rocks can lose mass and and size of rock fragments? Talk through this activity with pupils. Ask them to what to measure in step 4, which will be change shape. They consider what they should measure, predict what might happen, and how they might deal with step 4. Ask pupils, provided by more able pupils in the group or and how best to record and display their results.in mixed ability groups, to carry out the task on this worksheet. by the teacher.

15 Plenary. Settle pupils. Use Q and A to discuss their findings, and how they dealt More able pupils will appreciate the need to Pupils have a record of changes in mass and shape as rock with step 4. Using an interactive white board, or OHP, discuss their ideas on how calculate percentage change in mass, and will be fragments are transported. They use suitable methods to they might display their results (step 7 on the worksheet). Ask them to write up expected to do this when displaying their results record and display results so that valid comparisons can be their investigation. graphically. Less able pupils can be provided with made.

graph axes if required.

5 With the class, look at and discuss the diagram on page 131 of the Pupil Book. Pupils think about, and begin to learn the names of, the Set homework. different sizes of rock fragments carried by a river, including

those in solution.

Homework: Answer questions 2 and 3 on page 131 of the Pupil Book. Also question 4 on page 138 if they have time.


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Lesson Focus Pupil Book 2 pp. 132–135Formation of sedimentary rocks by deposition and evaporation

ExpectationsMost Pupils Know that when rock fragments are deposited they can be

compressed to form solid rock again, with the help of ‘cement’.Understand how evaporation can produce salt deposits.Understand that rock strata tell a story of past events.

Less Able Pupils Know that sand grains can be deposited and form sandstone. Knowthat salt deposits are formed when sea water evaporates. Knowthat rock strata tell a story of past events.

More Able Pupils All the above, plus appreciate why rocks with different sizes ofgrains are formed in different parts of a flood plain.



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Worksheet I6 Making sandstonePer group:20 cm3 plastic syringe with nozzle cut off,smeared with petroleum jelly on theinside of the barrel250 g wet sand10 g powdered clay10 g plaster of Paris powderDisposable cups and spoons for mixingGogglesTray on which to place pelletsMasses (for testing strength of ‘rocks’)

Worksheet I7 A story in the strata

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10 In and register. Pupils begin to appreciate that rock fragments may become Starter. Show the class a piece of sandstone and ask them to tell you what it is solid rock again. They use understanding of transport and made of (refer back to Worksheet I1 if necessary). Ask them to suggest how deposition by rivers to predict and explain how layers of sand grains being carried along by a river might become solid sandstone rock. sediment may be produced.Look at the diagram on page 133 of the Pupil Book and discuss how layers ofsediments may build up and compress the earlier ones.

15 Development. Distribute Worksheet I6 Making sandstone. Ask pupils to Pupils investigate the contribution of ‘cement’ to the carry out this investigation, as far as step 8. formation of ‘rock’ from sand grains.

5 Settle pupils. Discuss the river flood plain diagram again with them. Use Q Less able pupils will find it more difficult to Pupils use knowledge about the deposition of rock fragments and A to help them to answer the question at the bottom of page 133 of the visualise the transport and deposition of rock to explain the formation of layers of sediment in a flood plain.Pupil Book. fragments across a flood plain.

10 Ask pupils to read quietly, or ask one pupil to read aloud, the section More able pupils are more likely to recall earlier Pupils revise earlier knowledge and understanding of the role ‘Evaporation’ on pages 134–135 of the Pupil Book. Use Q and A to help them to work on evaporation and the formation of salt of evaporation in the formation of salt deposits, and apply this remember what they know (from Year 7) about the Dead Sea, and how rock salt deposits. in the context of sedimentary rock formation.deposits formed in Cheshire.

10 Plenary. Ask pupils to check their ‘rock’ samples from Worksheet I6. If these Pupils recognise that compression helps to form solid are dry enough, ask them: Which is the hardest? What does this suggest about sandstone from sand grains, but that ‘cement’ is also required.how sandstone might be formed from sand grains?Distribute Worksheet I7 A story in the strata, and set homework.

Homework: Worksheet I7. If time, find out limestone is formed.


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Lesson Focus Pupil Book 2 Chapter 9Formation of limestone and of fossils. End of Unit test

Expectations

Most Pupils Know how limestone rocks and fossils are formed. Demonstratesecure knowledge and understanding of rocks and weathering.

Less Able Pupils Know how limestone rocks and fossils are formed. Demonstratesome knowledge and understanding of rocks and weathering.

More Able Pupils All the above, plus give a logical and well-structured account incontinuous prose of the formation of sedimentary rocks.



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Pieces of limestone and chalk; samples offossils, some still embedded in rock;photographs of fossils in situ

If available, stimulus material relating toMary Anning


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10 In and register. More able pupils are likely to volunteer Pupils revise their knowledge and understanding of the Starter. Show pupils a piece of limestone. Ask them: What is limestone made of? information from their researches into how composition of limestone, and know how it was formed.How is it formed? limestone is formed.

10 Development. Show the class photographs of limestone rocks containing fossils. Pupils understand how fossils are formed in sedimentary Ask them: what are fossils and how are they formed? Introduce the story of rocks.Mary Anning (Literacy activity).

30 Plenary. Distribute the End of Unit test and ask pupils to complete it. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the End correctly and will attempt the extension question. of Unit test.

Homework: Do the Literacy activity about Mary Anning on page 136 of the Pupil Book.


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362

UN I T

You are going to look really closely at several different kinds of rocks.

1 You will need a results table in which to write your observations. Find outhow many different kinds of rocks you are going to investigate. Then drawa table like this one, with the right number of rows.

Leave big spaces to write in, because you might have quite a lot to sayabout the rocks.

2 Take the first sample of rock, and look at it really carefully. Use a hand lensor binocular microscope if possible. What can you see? If you can seeparticles or grains, what colours are they? Are they all the same, or arethere different kinds? How big are they? What shape are they? How dothey fit together? Are they dull or shiny? Are they arranged in anyparticular pattern – for example in layers – or are they just bundledtogether anyhow?

3 Shut your eyes, and run your fingertips gently over the surface of the rock.What does it feel like?

4 Take a small piece of the rock and put it gently into a beaker of water. Canyou see bubbles coming out? If so, where must they be coming from?

I1 What are rocks made of?CHAPTER

WORKSHEET1

9


Name of rock What does it look like? What does it feel like? What happens whenit is put in water?

granite

sandstone

limestone

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UN I T

I2 How does rain cause

weathering of rocks?

CHAPTER

WORKSHEET2

9


You are going to investigate the effects of rain on two different kinds ofrocks: limestone and granite.

To speed up your results, you are going to use ‘rain’ that contains quite a lotof acid. ‘Normal’ rain will have the same effects, but it will take much, muchlonger.

Acid rain and limestone1 Take a small piece of limestone and drop some dilute hydrochloric acid

onto it. Watch very carefully to see if anything happens.

2 Write a sentence or two describing what happened.

3 Limestone contains calcium carbonate. Think back to what you knowabout acids and how they react with carbonates. Try to explain what yousaw.

Acid rain and granite1 Look carefully at the surface of a piece of granite. The different coloured

grains in the granite are made of different minerals. (Minerals arechemicals that make up rocks.) You will probably be able to see:

• Quartz. This is usually grey. It is very hard and can scratch steel.

• Feldspar. This can be pink or white. The feldspar grains are often good crystal shapes, and they can be quite large in some kinds of granite. Feldspar is not as hard as quartz, and can be scratched with a steel pin.

• Mica. This often looks like little pieces of black, shiny glass. Mica can also be grey or whitish.

2 Your teacher will put a piece of granite into some acid,and another similar piece into water. Over the next fewlessons, look really carefully at the surfaces of these twopieces of granite. Note down any changes you can see,looking especially to see if the quartz, feldspar and micagrains are affected in the same way, or differently, by the acid.

Tip:The photograph

on page 129 of the

Pupil Book will

help you to

identify the

different grains.

Tip:If possible, use a

digital camera to

take photographs

of the granite

surface every

day. Then you

can make a

simple time-lapse

display on a

computer showing

the changes

speeded up.


➤continued

Heating and coolingYour teacher will hold a piece of dry rock in a flame until it gets very hot.Then the rock will be put into very cold water.

Watch carefully while this is done several times.

Freezing and thawing1 Take a small plastic bottle and fill it to the very top with water. Put the

bottle in a freezer and leave it until next lesson. Then take it out anddescribe what has happened.

2 Collect two pieces of two different kinds of rock, for example two piecesof granite and two pieces of limestone. Put one piece of granite and onepiece of limestone into a container, cover them with water and leave themin a safe place. Put the other two pieces into another container, coverthem with water and put them into a freezer. Leave them there until nextlesson.

UN I T

I3 How do temperature changes

cause weathering of rocks? (page 1)

CHAPTER

WORKSHEET3

9

1 What eventually happens to the rock? Write a shortexplanation of why this happens.

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I3 How do temperature changes

cause weathering of rocks? (page 2)

CHAPTER

WORKSHEET3

9


3 Take the container out of the freezer and let it thaw. (Your teacher may dothis for you, so that it is thawed already.) Compare the rock pieces that werefrozen and thawed with those that were not.

4 Over the next few days, put the ‘frozen’ rocks through several more freeze-and-thaw cycles. Each time you thaw them out, look carefully at them andcompare them with the unfrozen rocks.

2 Which kind of rock was more damaged by the repeatedfreezing and thawing? Try to suggest why this type of rockwas more damaged than the other type.

3 Use your results from step 1 (freezing the water in the plasticbottle) to explain why repeated freezing and thawing canbreak rocks apart.

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digital camera,

you could

photograph the

pieces of rock

after each time

they are frozen

and thawed. Then

you can make a

time-lapse

sequence to show

how they changed.

This is the apparatus you will use forthis investigation.

You are going to look at how the river picks up the sand and carries it away,and how it drops the sand again.

• Picking up the sand and moving it away from where it started from is called erosion.

• Carrying the sand along is called transport.

• Dropping the sand is called deposition.

You are going to try to answer two questions. Here is the first one:

Where does the water flow most quickly and where does it flow most slowly?

1 Let water run gently into the guttering. Add a little blue colouring to thewater, and watch where the colouring goes and how quickly it moves.

2 Make a sketch of the guttering, and label it to show where the water movesmost quickly and where it moves most slowly.

Here is the second question:

Where does the river erode and deposit the sand?

1 Empty all the water out of the guttering. Fill the guttering with sand towithin 2 cm of the top.

2 Let water run gently into the guttering as before. Watch carefully to seewhat happens to the sand.

3 Make a sketch of the guttering, and label it to show where the sand waseroded (picked up) and where it was deposited (dropped).

4 Can you see any connection between your answers to the first question, andyour answers to the second question? If you can, try to explain thisconnection, using the word ‘energy’.

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UN I T

I4 Investigating the transport

of rock fragments by rivers

CHAPTER

WORKSHEET4

9


inlet tube

clip

overflowing beaker

wooden block

overflow

sink

gutter end-piece

Source: this investigation is adapted from Activity 3 in ‘The Dynamic Rock Cycle’, available fromhttp://www.earthscienceeducation.com/handouts/ (accessed 5/12/02), based on Earth Science Teachers’ Association(1990) Science of the Earth 11–14, Second-hand rocks. Geo Supplies, Sheffield: ESTA.

367

You are going to investigate what happens to pieces of rock as they arecarried along (transported) in a river. If you have time, you can comparewhat happens to two or more different kinds of rock.

To make things happen a bit more quickly than they normally would (andalso so that you will not make quite so much mess) you are going to use a‘river’ without any water in it.

1 Collect four pieces of the first kind of rock. Make sure you know the nameof the rock, and write it down.

2 Use a top pan balance to find the total mass of your four rock fragments.Write this down.

3 Put the four rock fragments into a wide-topped plastic container, and putthe lid on very firmly. Now shake the container for exactly 10 seconds.

4 Take the top off and tip out the rock fragments.a Do they look any different now? Record your observations.b Pick up the four rock fragments, leaving any tiny grains behind. Find

their new mass, and record it.

5 Put all the rock fragments back into the container. Repeat steps 3 and 4four more times.

6 Now repeat steps 1 to 4 with a different kind of rock. If you have time, tryseveral different kinds.

7 Display your results so that you can easily see any differences in the effectsof transport on the different kinds of rock you have tested.

I5 How does a river change the

shape and size of rock fragments?

CHAPTER

WORKSHEET5

9


Source: this investigation is adapted from Activity 2 in ‘The Dynamic Rock Cycle’, available fromhttp://www.earthscienceeducation.com/handouts/ (accessed 5/12/02).

Tip:You will have to

decide how you

will select the

pieces to mass.

1 Collect some wet sand and put it inside a syringe. (The syringe has beensmeared with petroleum jelly on the inside, to make it easy for the sandgrains to slide into and out of it.)

2 Put the open end of the syringe onto the palm of your hand. Push theplunger in as hard as you can, to squash the sand grains as much aspossible.

3 Now carefully push the sand out of the syringe onto a piece of paper. Leavethis on a tray or piece of paper.

4 Take some more wet sand, and also some clay. Mix about three parts of thesand with one part of clay.

5 Repeat steps 1, 2 and 3 with the mixture you have made.

6 Take some more wet sand, and also some plaster of Paris. Mix about fiveparts of the sand with one part of plaster of Paris.

7 Repeat steps 1, 2 and 3 with the mixture you have made.

8 Leave all of your samples of ‘sandstone’ to dry.

9 When your rocks have dried, compare them. Try to think of different waysof doing this. For example, you could compare what they look like andwhat they feel like. You could also compare how strong they are – thinkabout how you could do this.

368

I6 Making sandstone9

CHAPTER

WORKSHEET6


Source: this investigation is adapted from Activity 4 in ‘The Dynamic Rock Cycle’, available fromhttp://www.earthscienceeducation.com/handouts/ (accessed 5/12/02), based on Earth Science Teachers’ Association(1990) Science of the Earth 11–14, Second-hand rocks. Geo Supplies, Sheffield: ESTA.

This diagram shows some sedimentary rocks. The different layers are calledstrata. The arrangement of the strata can tell us the story of what happenedin that area over millions of years of its history.

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I7 A story in the strataCHAPTER

WORKSHEET7

9


1 Which of the strata contains the oldest rocks? How can youtell?

2 Copy the diagram into your workbook. Next to each layer,write a description of how it was formed, using thesesentences. You need to decide what order they go in:

• A warm, shallow sea was present. Tiny skeletons and shellsmade of calcium carbonate fell to the bottom of the sea andcollected there.

• The climate became much hotter and drier. The sea dried up.

• The climate got so hot and dry that sandy deserts formed. Thewind blew sand into the area where the sea had once been.

• The climate became wetter again. The area again became ashallow sea.

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limestone B

sandstone

rock salt

limestone A


1 Choose one of these words to complete each of these sentences.

acid rain erosion limestone weathering

a The disintegration (breaking down) of rocks is called

..............................................................................................................................

(1)b Carrying away the rock fragments is called

..............................................................................................................................

(1)2 This diagram shows some layers (strata) of sedimentary rocks.

a Which is the oldest layer?

..............................................................................................................................

(1)b Suggest what was covering the land when the limestone layers formed.

..............................................................................................................................

(1)c What is limestone made of? Tick the correct box.

sodium chloridecalcium carbonatesand grainsgranite

(1)d Suggest how the sandstone layer might have been formed.

..............................................................................................................................

..............................................................................................................................

(2)

End of Unit test


CHAPTER

9

A limestone

B sandstone

C limestone sea

371

e Which layer or layers could contain fossils?

..............................................................................................................................

(1)3 a These sentences describe one way in which changing temperatures can

cause weathering of rocks. Write the letters of the sentences in the correct order, to describe how the weathering happens. The first one has been done for you.

A This involves contraction, so the water does not fill the crack any more.B The temperature rises above 0 °C, so the ice thaws and changes into

liquid water.C When it rains, water gets into cracks in the rock.D The temperature falls below 0 °C, so the water freezes and changes into

ice.E Eventually the rock is split into smaller pieces.F This involves expansion, which pushes out on the rock and makes the

cracks bigger.

..............................................................................................................................

(4)b Describe how changing temperatures can cause weathering of rocks even

if there is no water present.

..............................................................................................................................

..............................................................................................................................

(2)4 This graph shows the biggest rock fragments which can be carried by water

flowing at different speeds.

a How fast does a river have to flow in order to be able to carry pebbles along?

..............................................................................................................................

(1)



C,

clay silt sand gravel pebbles cobbles/boulders

Riv

er v

elo

city

(cm

/s)

1000.0100.010.01.00.10.010.001

Size of particles (mm)

particles transported

particles deposited

1000

100

10

1

0.1


b How fast does a river have to flow in order to be able to carry silt along?

..............................................................................................................................

(1)c Which sizes of fragments can a river flowing at 10 cm per second carry?

..............................................................................................................................

(3)

5 James wanted to show how granite could become a sedimentary rock. This iswhat he did.

a Stage 1 representedweathering. The granite was made of grains of

feldspar, mica and quartz. Which one of these three kinds of grains would not be changed during Stage 1?

..............................................................................................................................

(1)b Stage 2 represented the fragments of granite being transported by a

river. Describe how the fragments would change as they were transported in the water.

..............................................................................................................................

(2)



c Rivers do not usually flow into sieves. Suggest what process James was trying to represent with Stage 3 of his rock-making experiment.

..............................................................................................................................

(1)d In stage 5, James used heavy masses to compress the rock particles. How

would they be compressed in a natural rock-making process?

..............................................................................................................................

(1)e The fragments in the ‘rock’ that James made were mostly sand grains.

What name do we give to a rock made of sand grains?

..............................................................................................................................

(1)

Total marks: 25

Extension question

6 When a river floods, it spreads over an area called a floodplain. Use thegraph in question 5, and your own knowledge, to explain how sedimentaryrocks such as siltstones and sandstones can be formed on the floodplains ofrivers.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(10)




Text answers1 a Granite mountain – freezing and thawing

b Sandstone desert – heating and coolingc Limestone – acid rain

2 a The largest fragments – gravel and sandb Solutes/solublec Heat the water so that the water evaporates

3 The faster/slower a river flows, the more/less energy it has. So fast-flowingrivers can carry bigger/heavier particles than slow-moving rivers.

Literacy activity answersAnswers will vary

End of chapter answers1 a The breaking down of a rock into fragments – weathering

b Removing the fragments of rock from where they were formed – erosionc Dropping the fragments of rock in a different place – depositiond The chemical substances that make up rocks – minerals

2 a Weatheringb Erosionc Weathering

3 Answers will vary4 The rock fragments will drop out of the water, because the water in the

river slows down as it enters the sea and has less energy.5 Answers will vary

Worksheet answersWorksheet I7 A story in the strataThe descriptions should be written in this order, reading from the bottom up:A warm shallow sea...The climate got so hot...The climate became much hotter...The climate became wetter...

End of Unit test answers1 a Weathering (1)

b Erosion (1)2 a Limestone C (1)

b A sea (1)c Calcium carbonate (1)d Sand grains; from weathered sandstone/from a desert; carried by

water/carried by wind; and deposited; compacted/cemented(any two for 2 marks) (2)e All of them (1)

Rocks and weatheringC

HAPTER

9

ANSWERS


3 a (C), D, F, B, A, E(lose 1 mark for any one pair of letters out of sequence) (4)b The rock expands when it is heated; and contracts when it cools (2)

4 a 80 cm/s (1)b just over 0.01 cm/s (1)c clay, silt and sand (3)

5 a Quartz (1)b Get smaller; become more rounded (2)c Deposition/rock fragments being dropped by the river as it slows down (1)d Other layers forming on top of them (1)e Sandstone (1)

Total marks: 25

Extension answers6 This is a difficult exercise for pupils, testing their ability to imagine and

describe a complex sequence of events. Give credit for the following:

• flooding river has a lot of energy/water flows fast• carrying rock fragments of many different sizes/large size• water slows down as it spreads across the flood plain• dropping the rock fragments• the slower the water, the smaller the fragments it drops• similar-sized fragments dropped, at the same time/in the same place• larger fragments/sand grains, dropped closer to the river (channel) than

smaller ones• over long periods of time, many flooding events• many layers form• the weight of the top layers compresses the lower layers• water carrying chemicals seeps in between grains and the chemicals

crystallise to form ‘cement’• if fragments were between 0.1 and 1.0 mm in diameter they form sandstone• if between 0.01 and 0.1 they form siltstone• siltstone will form further away from the river (channel) than sandstone



Chapter 9 Answers

Pupils should be familiar with the following ideas:• There are rocks under the surface of the Earth• Soils come from rocks• Rocks have different textures• Weathering affects rocks• Solids, liquids and gases are made of particles

10 The rock cycle

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QC

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f W

ork

Re

fere

nc

e:

Un

it 8

H

Starting points


BasaltEruptGraniteIgneous rock

LavaMagmaMarbleMetamorphic rock

MoltenMudstoneObsidianPumice

Slate

In this topic pupils should learn:• about the major rock-forming processes• how rock-forming processes are linked by the rock cycle• to use the concept of rock texture as one of the key characteristics of igneous,

sedimentary and metamorphic rocks• to relate processes observed in other contexts, e.g. crystallisation, to processes

involved in the rock cycle• to consider processes operating on different timescales• to model rock-forming processes• to investigate a technique for comparing the composition of limestones,

evaluating different approaches• to investigate differences between igneous rocks using both first-hand and

secondary data

Learning checklist

Links

7.5HRS

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Unit Title7F Simple Chemical Reactions7G Particle Model of Solids, Liquids and Gases7I Energy Resources8F Compounds and Mixtures8G Rocks and Weathering8I Heating and Cooling


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Cross-curricular linksGeography Unit 2 ‘The restless earth – earthquakes and volcanoes’, Unit 13‘Limestone landscapes of England’ and Unit 21 ‘Virtual volcanoes and internetearthquakes’

LiteracyThere is a literacy activity on Eruption at Goma in the Pupil Book. Lesson 5 askspupils to write a news report on an erupting volcano.

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Scientific enquiry• Suggest how they could investigate the carbonate content of a limestone rock• Interpret data from secondary sources and their own observations of rocks and

about differences between volcanoes and relate this to processes of formation• Draw conclusions from their data and describe how their own conclusions are

consistent with the evidence obtainedMaterials and their properties• Describe and explain how sediment becomes sedimentary rock• Describe the conditions under which metamorphic rock is formed and how

igneous rocks crystallise from magma• Relate crystal size to rate of cooling• Describe some distinctive features of igneous, sedimentary and metamorphic

rocks and use these to distinguish between the rock types

Pupils who have not made so much progressScientific enquiry• Describe the results of their investigation• Use data from secondary sources and identify differences between different

rocksMaterials and their properties• Name the three types of rock and give some examples of each• Describe some characteristics of each rock type• Explain that high temperature and pressure can change existing rocks into

different types of rocks

Pupils who have progressed furtherScientific enquiry• Evaluate data obtained, indicating how confident they are in their conclusionsMaterials and their properties• Explain in terms of the particle model how different rates of cooling lead to

different crystal sizes• Bring together physical and chemical processes to explain the formation of

different rock types and the rock cycle• Relate composition to the process of formation

Learning outcomes


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The chapter begins with a photograph of a rock formation that pupils shouldrecognise as being unlikely to be formed by the processes they have so far learntabout, and so introduces the idea that there are other ways by which rocks can beformed. You might like to use something more dramatic, such as a video clip of avolcano erupting, to introduce this idea. However, if you have moved into thischapter directly from Chapter 9, Rocks and weathering, you could skip this andgo straight into Question 1 or Worksheet J1, Identifying sedimentary rocks, asthese continue the line of thought from topics covered in Chapter 9.

Worksheet J1, Identifying sedimentary rocks, provides an opportunity for pupils tolook at several types of sedimentary rock and begin to recognise features thatthey can use to identify them. The samples you use will, of course, depend onavailability, but you should certainly provide at least one type of limestone andsandstone, plus your local rock, and others if possible, for example conglomerateand mudstone or siltstone.

You might prefer to do the hydrochloric acid test as a demonstration, eitherbefore or after the pupils look at and record the texture of the rocks. If they dothis themselves, you must obviously be certain that pupils do not leavehydrochloric acid in places where other pupils might unknowingly come intocontact with it.

Safety pointsEye protection will be needed when acids are used.

Pupils could then go on to answer Question 1 on page 139, which summarisesthe main ideas that they have learnt about sedimentary rocks.

Worksheet J2, Comparing the calcium carbonate content of two samples oflimestone, is quite a difficult planning exercise for pupils at this stage. Theworksheet gives them some hints about the strategies they might use, but you willalmost certainly need to talk this through with them. There are several possibleapproaches, and it would be good if different groups tried different methods. Thethree basic techniques are:• measuring the volume of acid that is needed until the reaction is complete,

identified by no more fizzing occurring, or perhaps using indicators to monitorpH changes;

• measuring the volume of gas that is given off when excess acid is added, forexample by collecting it in a gas syringe, or timing how long it takes for limewater to reach a certain degree of cloudiness.

• collecting the material left in the beaker after the calcium carbonate hasdissolved, by filtering, then finding its mass.

Note that unless pupils use very small amounts of limestone, they will need touse large volumes of acid.

There is no need for pupils to measure precisely, but only to obtain comparativefigures for the two rock samples. Whichever method they use, there will be anumber of variables to be controlled. A discussion of how satisfied they are withtheir method and results will be very important, so allow plenty of time for this.Encourage them to include a discussion about this when they write up theirinvestigation.

Safety pointsEye protection will be needed when acid is used.!

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Teachers will need to check pupils’ plans for health and safety beforepractical work starts.

Igneous rocksThis topic can be introduced with video clips of volcanic eruptions, which arealways guaranteed to stimulate interest. Try to include some shots of lava coolingand forming rocks.

Pupils may already know that the temperature gets higher the deeper you go intothe Earth. The high temperature is maintained by the radioactive decay of elementsbelow the surface. Pupils have several new terms to learn – molten, magma andlava – and will need to be encouraged to use these correctly when they discuss orwrite about these topics. They may be able to tell you that ‘ignite’ is another wordbeginning with ‘ign’ which means ‘to do with heat’. This is also a good opportunityto revise understanding of the particle model of melting and solidifying.

Worksheet J3, How does rate of cooling affect crystal size?, uses salol to representlava. Salol is phenyl salicylate, and is non-toxic, but pupils should nevertheless takecare when handling it, as they would any chemical. It is easier to see the crystalsforming if the slides are placed on coloured paper. Make sure that the ‘freezer’slides are placed into the freezer at least one hour before the lesson. Pupils shouldsee that the salol forms noticeably larger crystals when using the ‘roomtemperature’ slides than with the ‘freezer’ slides, and can use this observation topredict even larger crystals with the ‘warm’ slides. The whole class can see theresults if the slides are put onto an overhead projector.

Safety pointsSalol is low hazard, but eye protection should be worn.

Worksheet J4, Detecting how igneous rocks were formed, asks pupils to apply theknowledge gained from Worksheet J3 to their observations of four types ofigneous rocks. They should see that granite has much larger crystals than basalt,and so be able to predict that granite has cooled more slowly. Obsidian has novisible crystals at all and so has cooled even more rapidly than basalt, while pumicealso has very tiny crystals (probably invisible). The spongy nature of pumice leadson to thinking about how this rock might have been formed.

All of this can now be used to explain how granite forms from slowly coolingmagma beneath the Earth’s surface. The granite rocks of Cornwall are a goodexample of this; in places, the rocks that originally overlaid the granite have beenworn away, and we see the granite exposed as tors. Basalt forms from more rapidlycooling lava, while obsidian and pumice have cooled even more rapidly. You couldalso show pupils video clips of lava flowing into sea water and cooling, formingrocks called pillow basalt (see photo on page 141).

Granite and basalt differ in their composition. The magma that cooled to formgranite contained relatively large amounts of quartz; if this type of magma coolsabove the surface it forms fine-grained rocks called rhyolite. The type of magmathat forms basalt, on the other hand, contains little or no quartz and more ironthan granite, so basaltic rocks are more dense than granite rocks. If this type ofmagma cools slowly beneath the surface, it forms gabbro. This difference incomposition means that granite and rhyolite are less dense than basalt and gabbro.However, this is probably a step too far to take most pupils at this stage.

Volcanic eruptions are often in the news, and pupils may be interested in thinkingabout the impact of volcanic activity on humans. There are numerous web sitesthat document current and recent volcanic eruptions, and of course there are alsonumerous very well-known historic events, such as the burying of Pompeii and the

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eruption of Krakatoa. The literacy activity focuses on the 2002 eruption ofNyiragongo, near Goma in the Democratic Republic of Congo – at a time whenthe country was already considerably disrupted by political unrest and fighting.

Metamorphic rocksBoth sedimentary and igneous rocks can be transformed by high temperatures,high pressures or both. As pupils will not deal with plate tectonics and large-scalerock movements until Key Stage 4, the causes of metamorphism are kept simple atthis stage. It is suggested that you concentrate on two examples: contactmetamorphism of limestone to form marble, and the realignment of flakyparticles in mudstone to form slate. Worksheet J5, Metamorphic rocks, asks pupilsto look at at least two types of sedimentary rock and their metamorphicequivalents, and to compare them. Encourage them to consider what processeshave resulted in the changes that they see.

A common error is to think that metamorphic rocks cannot contain fossils.Obviously, if the degree of metamorphism is high, then fossils will be so alteredthat they lose their identity, but some metamorphic rocks do still contain fossils.Slate, for example, is often a source of recognisable fossils, albeit squashed anddistorted ones. Worksheet J6, What happens to fossils during metamorphism?, helpspupils to understand this, and to use the appearance of the fossils to work outwhat forces must have been acting on the sedimentary rock in which they werecontained.

Now that pupils know something about sedimentary, igneous and metamorphicrocks, they are in a position to begin to consider how these three rock types mayinterrelate. Worksheet J7, The rock cycle, provides a partial framework into whichpupils can fit rocks and processes to show how the materials from which one typeof rock is formed can become a different type of rock. However, it is suggestedthat, before giving them this worksheet, you build up an outline rock cycle withthem, asking them to suggest all the different ways in which one rock mightbecome a different rock. This will require bringing together the concepts fromChapter 9 as well as Chapter 10, and so makes an excellent revision exercise. Thepupils’ final version of the diagram should be kept in their workbooks, as thePupil Book does not contain this diagram.

The rock cycle shown on Worksheet J7 is a simplified one, because it restrictsitself to processes covered by pupils so far. Later, when they cover plate tectonicsat Key Stage 4, they will be able to add further processes to provide a morecomplete picture.



Sc1

Scientific Enquiry

2a, 2j (partially), 2k

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Physical Processes



Erupt

Slate

Basalt

Marble

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Igneous rock

Magma

Metamorphic rock

Molten

Lava

Pumice

Obsidian

Mudstone


• I know how sedimentary rocks areformed

• I can give some examples ofsedimentary rocks

• I can use rock texture to tell thedifference between igneous,sedimentary and metamorphicrocks

• I know that rocks deep in the Earthget so hot that they melt and formmagma

• I know that when magma comesout onto the surface of the Earth itis called lava

• I know that when magma or lavacools and solidifies it forms igneousrocks

• I know that sedimentary or igneousrocks can become metamorphicrocks if they undergo greatpressure or heating

• I can compare the calciumcarbonate content of limestonesamples

• I know how rock-forming processesare linked in the rock cycle

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The rock cycle

CHECKLIST

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Lesson Focus Pupil Book 2 p. 139Identifying sedimentary rocks

Expectations

Most Pupils Use appearance and reaction with hydrochloric acid to identify arange of sedimentary rocks.

Less Able Pupils Use appearance and reaction with hydrochloric acid to identifysome sedimentary rocks.

More Able Pupils All the above, plus use appropriate terminology with confidence.



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Worksheet J1 Identifying sedimentaryrocksNamed sedimentary rocks distributedaround the laboratory as a circus – toinclude sandstone, limestone plus at leastone other typeSmall bottles of dilute hydrochloric acidPaper towels or J cloths for wiping acidoff rock samplesA different example of one of the namedrock types, labelled Rock XHand lensesGoggles

Worksheet J2 Comparing the calciumcarbonate content of two samples oflimestone

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5 In and register. More able pupils will remember how sedimentary Pupils revise their knowledge of the formation of sedimentary Starter. Look at the photograph of basalt columns on page 139 of the Pupil Book. rocks are formed, and volunteer information. rocks. They begin to recognise that there must be other ways Ask pupils: Could this be a sedimentary rock? Use this to lead into a revision of in which rocks are formed.sedimentary rock formation.

5 Development. Distribute Worksheet J1 Identifying sedimentary rocks. Tell pupils how many rows they will need in the table and ask them to copy it into their workbook.

5 Explain where the rock samples are, and allocate each group to a starting point. Emphasise safety with hydrochloric acid – wear goggles, how to clean acid from samples.

15 Ask pupils to complete Worksheet J1. Support them as they work. Less able pupils will require help to make Pupils become familiar with the appearance of a range of observations and record them appropriately. sedimentary rocks. They use HCl to identify limestone.

10 Plenary. Settle pupils. Discuss their observations on each rock sample. Ask each Pupils consolidate their knowledge and understanding of group in turn what they decided Rock X is, and confirm the correct identification. sedimentary rock formation and types. If time, do question 1 on page 139 orally, with the class.

10 Distribute Worksheet J2 Comparing the calcium carbonate content of two More able pupils will be able to see more than Pupils begin to apply their knowledge of reactions of acids samples of limestone and set homework. Talk through the possible approaches one possible way of carrying out this investigation. with carbonates to plan this investigation, including the with pupils. Discuss control of variables, and what they will measure and how. Less able pupils will need considerable guidance, control of variables.

and can be given a help sheet.

Homework: Worksheet J2 – produce a plan to be carried out next lesson.


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Lesson Focus Pupil Book 2 –Comparing the calcium carbonate content of two samples of limestone



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Spare copies of Worksheet J2Comparing the calcium carbonatecontent of two samples of limestonePer group:Two samples of different types oflimestone, with markedly differentcalcium carbonate content (e.g. chalk andironstone), each broken into small piecesBottle of 1 mol dm–3 hydrochloric acidTwo conical flasksTest tubes and rackBungs and delivery tubes for test tubesStop watchAccess to top pan balanceLime waterMeasuring cylinder or other method ofmeasuring volumes of acidBeakerGas syringeGoggles

ExpectationsMost Pupils Contribute substantially to the production of a plan for this

investigation, and use it to obtain results which enable them todecide which rock contains the more calcium carbonate. Considerother possible approaches.

Less Able Pupils Make some useful contribution to the production of a plan for thisinvestigation, and use it to obtain results which enable them todecide which rock contains the more calcium carbonate. Be awarethat there are other possible approaches.

More Able Pupils All the above, plus instigate changes in the original plan whileworking. Make a realistic evaluation of their method and suggesthow it could be improved. Make an informed comparison of otherpossible methods of carrying out this investigation.

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5 In and register.Starter. Ask pupils to look out Worksheet J2 Comparing the calcium carbonate content of two samples of limestone. Settle them in groups, and explain what they are going to try to do.Safety! Remind pupils about care with acids.

10 Development. Ask groups to discuss the plans that each pupil in the group has More able pupils are likely to lead the group Pupils cooperate and use ideas from individual group suggested, and to decide on the best one. Ask: Is everyone reasonably happy discussion, and to have their plans accepted by members to decide on the ‘best’ way to carry out the they know what they are going to do? Provide help and suggestions to any the group. Less able pupils will be encouraged to investigation.groups who are still unsure. contribute.

25 Ask groups to carry out their plans. Question them as they work, checking they More able pupils will recognise shortcomings as Pupils use their ideas to carry out an investigation, including understand what they are doing. Use questioning to help them to improve their they work and make modifications to the plan. the control of variables. They measure and record results. They experiment and techniques. Ensure each pupil keeps a record of the results their Less able pupils will be encouraged to contribute. use their results to draw a conclusion.group obtains.

10 Plenary. Tidy away and settle. Ask: Which of the two samples had the more Less able pupils will need supportive questioning Pupils evaluate their methods, and consider how they calcium carbonate? Ask groups who used different methods to briefly describe to bring out suggestions for shortcomings of their compare with different methods used by other groups. what they did. Ask: Do you think one method is better than the others? For each methods.method, what do you think the main problems were? How would you do things Any pupils with no results will be provided with differently if you could do it again? Set homework. a set from another group.

Homework: Write up the investigation.


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Lesson Focus Pupil Book 2 p. 140Introduction to igneous rocksHow rate of cooling affects crystal size

ExpectationsMost Pupils Know and use confidently the terms molten, magma and lava.

With guidance, use particle theory to explain why magma solidifiesas it cools. Use salol to investigate the effect of rate of cooling oncrystal size, and know that faster cooling produces smaller crystals.

Less Able Pupils Know the meanings of terms molten, magma and lava. Use salol toinvestigate the effect of rate of cooling on crystal size, and knowthat faster cooling produces smaller crystals.

More Able Pupils All the above, plus use particle theory with confidence to explainwhy magma solidifies as it cools.



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Video clips of volcanic eruptions

Optional: video clip of lava flowing intosea water

Worksheet J3 How does rate ofcooling affect crystal size?Per group:Access to salol, kept at 40 °C in a waterbathA piece of rough paper, approx. A4Two microscope slides at roomtemperatureAccess to two microscope slides in afreezerAccess to two hand-hot microscope slidesin a warm incubatorDropper pipetteGogglesOptional: coloured paper

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10 In and register. Pupils know that igneous rocks are formed when molten rock Starter. Show pupils video clips of a volcanic eruption. Ask: What do you think cools.happens when the lava cools? Use this to introduce the idea of igneous rocks.

10 Development. Explain to pupils that rocks deep below the Earth are so hot that More able pupils will be able to apply their Pupils learn the meanings of some terms associated with they melt. Introduce the terms molten, magma, lava. With the class, discuss the knowledge of particle theory to explain what igneous rock formation. They apply their knowledge of answer to question 2 on page 140 of the Pupil Book. happens when magma or lava cools. particle theory to melting and solidifying rocks.

20 Distribute Worksheet J3 How does rate of cooling affect crystal size? Talk Pupils see for themselves how different rates of cooling affect through to ensure pupils know what they are going to do, and the purpose of crystal size. They use their findings to make a prediction, and the investigation. Then ask pupils to carry out this practical. then check this prediction by experiment.

10 Plenary. Ask pupils: What did you find? Discuss the relationship between rate More able pupils will be able to make a clear of cooling and crystal size. Ensure everyone has a set of results, then set statement about this relationship.homework.

Homework: Write up the practical on Worksheet J3.


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Lesson Focus Pupil Book 2 pp. 140–142Apply knowledge of effect of rate of cooling on crystal size to the appearance andformation of different types of igneous rocks

ExpectationsMost Pupils Use visible evidence, and knowledge of crystal size and rate of

cooling, to suggest how some types of igneous rocks were formed.With some help, write summaries of how four types of igneousrocks were formed.

Less Able Pupils With support, use visible evidence, and knowledge of crystal sizeand rate of cooling to suggest how some types of igneous rockswere formed. With considerable help, write summaries of how fourtypes of igneous rocks were formed.

More Able Pupils All the above, with confidence.



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Worksheet J4 Detecting how igneousrocks were formedPer group:Samples of basalt, granite, obsidian andpumice, each labelled with their namesHand lens

Video clips of lava cooling under the sea

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5 In and register. More able pupils will volunteer information. Less Pupils consolidate their knowledge of the terms lava and Starter. Ask pupils: When lava cools, what is the name for the type of rock able pupils will be encouraged to contribute by igneous rocks. They recall their understanding of the effect of formed? If it cools quickly, what does this mean about the size of crystals the use of constructive questioning. rate of cooling on crystal size.that form?

20 Development. Hand out Worksheet J4 Detecting how igneous rocks were Less able pupils will be given support as they Pupils apply their knowledge of the effect of rate of formed. Show them the four types of rock they are going to look at, and tell work, to help them to remember and apply cooling on crystal size to suggest how different types of them the names of the rocks. Ask pupils to work through the worksheet, their knowledge to answer the questions. igneous rocks may have been formed. They become answering the questions in their workbooks as they go along. familiar with the appearance and names of some igneous

rocks.

15 Plenary. Tidy away and settle. Talk through the answers to each question. Then Less able pupils can be given a partially Pupils consolidate and summarise their knowledge of how use photographs and diagrams on pages 140–142 of the Pupil Book to relate completed sheet on which to write their different types of igneous rocks were formed.their findings to the ways in which basalt, granite, obsidian and pumice are summaries.formed. Help pupils to write brief summaries of how and where these four types of igneous rock were formed.

10 If available, show video clips of lava cooling under the sea to form pillow basalt. Pupils see what happens as lava cools under the sea, and thus Set homework. understand the forms taken by pillow basalt.

Homework: Find information about a volcano that is erupting now, or has erupted very recently, using the internet, ready to make a poster next homework.


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Lesson Focus Pupil Book 2 pp. 140–142; 145How volcanic eruptions may affect people; preparing a news report

Expectations

Most Pupils Appreciate some of the ways in which a volcanic eruption canaffect people; produce a brief news report of a volcanic eruption.

Less Able Pupils Begin to realise some of the ways in which a volcanic eruption canaffect people. Make a reasonable attempt to write a brief newsreport of a volcanic eruption.

More Able Pupils All the above, plus be able to produce a perceptive news report,and to pick out features to describe what makes a good newsreport.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Using an appropriate style for presenting information in a brief news report.Numeracy:ICT:

Cross-curricular developmentGeography Unit 2 ‘The restless earth – earthquakes and volcanoes’ and Unit 21 ‘Virtual volcanoes and internet earthquakes’.

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Video clips of damage and disruptioncaused by a recent volcanic eruption

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10 In and register. More able pupils will volunteer information from Pupils consider the impact of volcanic eruptions on people Starter. Ask pupils: What happens when a volcano erupts? If available, show their research (last lesson's homework). living nearby.video clips of the damage and disruption caused by a recent volcanic eruption. Ask pupils: Why do people live near volcanoes, even though they know they are dangerous?

10 Development. Ask one or two pupils to read aloud the literacy activity passage Less able pupils may need more time, and perhaps Pupils revise their understanding of how water-borne diseases ‘Eruption at Goma’ on page 145 of the Pupil Book. more than one reading, to take on board the main can be spread.Discuss with them the dangers faced by the people living in Goma. Discuss the points in the passage. They are likely to need answer to question b and use this to revise understanding of the cause and guidance in how to prepare a summary for a news method of spread of cholera. report.

15 Settle pupils in pairs, and ask them to do question c. Pupils select information and try to summarise it in an appropriate form for a brief news report.

15 Plenary. Ask a representative from three or four pairs in turn to deliver their Pupils consider the features of a good news report.‘news report’ to the rest of the class. Ask: what does the class think makes a good news report? Set homework.

Homework: Make a poster to illustrate a recent volcanic eruption, using material researched for last homework.


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Lesson Focus Pupil Book 2 pp. 143–144Metamorphic rocks

Expectations

Most Pupils Describe some of the features of slate and marble. Know that slateis formed from mudstone and marble is formed from limestone.Understand how high pressure and temperature may cause theserocks to form.

Less Able Pupils Recognise slate and marble. Know that they are formed by highpressure and temperatures.

More Able Pupils All the above, plus use appropriate terminology with confidence.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Calculating densities.ICT:


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Worksheet J5 Metamorphic rocksPer group:Samples of mudstone and slate,limestone and marbleMeasuring cylinders big enough to takerock sample or Eureka can, beaker andmeasuring cylinderAccess to top pan balanceHand lensOptional: copies of the Worksheet forresults for the second pair of rocks

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10 In and register. More able pupils will volunteer information about Pupils learn the term ‘metamorphic’. They begin to Starter. Ask pupils: What are the two major types of rock you know about? sedimentary and igneous rocks. understand how metamorphic rocks are formed.How is each type formed? Introduce the idea of a third type, metamorphic rocks. Using pages 143–144 of the Pupil Book, discuss how pressure and high temperatures can change a rock.

25 Development. Distribute Worksheet J5 Metamorphic rocks. Ask pupils: Less able pupils will need help to remember how Pupils become familiar with the appearance and names of two How will you find the density of a rock sample? Ask them to complete the to find the density of a rock. More able pupils types of metamorphic rock. They use observations to describe worksheet. could be expected to work out which rocks are the differences between rocks. They revise their understanding

sedimentary and which are metamorphic. of how to use displacement to find density.

15 Plenary. Tidy up and settle. Discuss findings, and ask pupils for their suggested Pupils summarise ways of identifying metamorphic rocks. They answers to step 5 on Worksheet J5. Help pupils to decide on the best advice understand some of the uses we make of slate and marble. for distinguishing between sedimentary and metamorphic rocks, and help them They consolidate knowledge that slate is formed from to write this down. Discuss the uses we make of slate and marble. Set homework. mudstone, and marble from limestone.

Homework: Questions 1, 2 and 3 on page 147.


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Lesson Focus Pupil Book 2 pp. 143–144Interrelationships between different kinds of rocks, and processes involved in theirformation

ExpectationsMost Pupils Know that metamorphic rocks may contain distorted fossils.

Understand a simple rock cycle showing some of the ways bywhich one type of rock may become transformed into anothertype.

Less Able Pupils Know that forces may cause distortions of fossils in rocks. Knowsome of the ways by which one type of rock may becometransformed into another type.

More Able Pupils All the above, plus use knowledge to devise a diagram showing asimple rock cycle.



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Worksheet J6 What happens to fossilsduring metamorphism?Per group:Enough modelling material to make amouldA shell that can be pressed into themodelling material50 g of plaster of Paris powderAn old or disposable cup for mixingplasterGlass stirring rod

Worksheet J7 The rock cycleFor homework

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5 In and register. Pupils begin to think about how pressure may alter the Starter. Ask pupils: What is a metamorphic rock? What do you think happens to appearance of fossils. They appreciate that metamorphic rocks the fossils in a sedimentary rock when it becomes a metamorphic rock? may contain fossils.

25 Development. Distribute Worksheet J6 What happens to fossils during Pupils investigate how different directions of squeezing affect metamorphism? Make sure everyone understands what to do, and organise the appearance of fossils.into pairs of groups. Ask them to carry out this practical.Warning: do not pour plaster of Paris down the sink; wash glass rod immediately after use.

15 Plenary. Begin to pull together understanding of relationship between all three More able pupils will more quickly see how one Pupils are involved in thinking out a simple diagram of the rock types by asking the class: Could a metamorphic rock become a sedimentary type of rock may eventually become another type rock cycle.rock again? Could an igneous rock become a sedimentary rock? Could a and will play an active part in building up a rock sedimentary rock become an igneous rock? cycle diagram. They may volunteer information With pupils, build up an outline of a simple rock cycle. relating to plate tectonics.

5 Distribute Worksheet J7 The rock cycle and set homework.

Homework: Worksheet J7.


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Lesson Focus Pupil Book 2 Chapter 10Rock identification quizEnd of Unit test

ExpectationsMost Pupils Identify several different rock specimens. Demonstrate secure

knowledge and understanding of different rock types and theirmethods of formation.

Less Able Pupils Identify some different rock specimens. Demonstrate someknowledge and understanding of different rock types and theirmethods of formation.

More Able Pupils All the above, plus use knowledge and understanding to interprethow a group of rocks may have been formed and the relationshipsbetween them.



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Rock identification quiz

Samples of at least 10 different rocks,labelled with letters and distributedaround the room (multiple samples ofeach rock if possible)


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20 In and register. Pupils consolidate their knowledge of the appearance and Starter. Arrange class into groups. For the rock identification quiz, give pupils names of a range of different types of rock.10 minutes to identify as many as possible of the rocks placed around the room.Then check answers and ask each group to tell you their score.

30 Development. Distribute the End of Unit test and ask pupils to complete it. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the End Set homework. correctly and will attempt the extension question. of Unit test.

Homework: Make a word search using all the Key Words for both Chapter 9 and Chapter 10.


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You are going to look very closely at some different kinds of sedimentaryrocks, and write down their important features.

Then you can use what you have recorded to help you to identify anunnamed rock sample.

1 Copy and complete this table. Your teacher will tell you how many rowsyou need.

2 Look carefully at the first rock sample. Use a hand lens to help you to lookmore closely. Write the name of the rock in the table, and fill in the twocolumns about the grains in it.

3 Put your safety goggles on. Carefully drop a little hydrochloric acid ontothe rock sample, and watch what happens. Record your observations in thelast column.

Very important! Use a damp cloth to wipe the hydrochloric acid off thesurface of the rock, ready for the next group to test it.

4 Repeat steps 2 and 3 for each of the other rock samples.

5 Now try to identify Rock X. Copy and complete this sentence:

I think that Rock X is ........................................................................because

............................................................................................................

............................................................................................................

............................................................................................................

J1 Identifying sedimentary

rocks

CHAPTER

WORKSHEET1

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Name of rock Can you see If you see grains, What happens if you dropgrains in it? how big are they? hydrochloric acid on it?

!

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J2 Comparing the calcium

carbonate content of two

samples of limestone

CHAPTER

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10


Limestone is a sedimentary rock. Limestone always contains a lot of calciumcarbonate, but it can contain other substances as well.

Your teacher will give you two different kinds of limestone. You are going totry to answer the question:

Which sample of limestone contains the most calcium carbonate?

Here are some facts that might help you with your plan:

• Calcium carbonate reacts with hydrochloric acid like this:

• The carbon dioxide that is formed is given off into the atmosphere. Themore calcium carbonate there is, the more carbon dioxide will be givenoff.

• The more calcium carbonate there is in the rock, the more acid will beneeded to react with it all.

Think about what you will do, and then write out your plan, using theseguidelines to help you:

1 What are you going to do to your two samples of limestone, to comparetheir calcium carbonate content?

2 What variables will you keep the same, to make it a fair test?

3 What will you measure? How will you measure it?

4 What materials and apparatus will you need?

5 What do you think will happen?

6 Why do you think this will happen?

7 How will you carry out the experiment?

8 What safety measures do you need to take?

9 How will you record your results?

calcium carbonate + hydrochloric acid � calcium chloride + carbon dioxide + water


Molten rock, called magma, forms solid rocks when it cools down. You aregoing to investigate whether the rate at which it cools affects the size of thecrystals in the rock that is formed.

You cannot use real magma in this investigation, because you would have toheat rocks up to 1000 °C or more to make them liquefy. Instead, you aregoing to use a substance called salol. Salol behaves very like magma, but itmelts at about 40 °C.

1 Take a piece of paper and label it as shown in the diagram. Put a cleanmicroscope slide on the ‘room temperature’ part of the paper. Keepanother slide close by, ready for step 3.

2 Now collect two more clean microscope slides which have been chilled in afreezer. Put one of them on the ‘freezer’ part of the paper.

3 Collect some melted salol in a dropper pipette. Quickly put a few drops onthe ‘freezer’ slide and a few drops onto the ‘room temperature’ slide.Carefully put another ‘freezer’ slide on the first one, to make a salolsandwich. Do the same with your second ‘room temperature’ slide.

4 Watch what happens. You should see crystals forming. Make a note of:

• in which slide sandwich the crystals formed first;• in which slide sandwich the crystals grew fastest;• in which slide sandwich the biggest crystals were produced.

5 Predict what would happen if you repeated your experiment using warmslides. Why do you think this would happen?

6 Collect two warm slides, and repeat step 3. Watch what happens. Was yourprediction correct?

Source: this investigation is adapted from Activity 6 in ‘The Dynamic Rock Cycle’, pp. 13–14, available from

http://www.earthscienceeducation.com/handouts/ (accessed 5/12/02), based on Earth Science Teachers’ Association (1990)

Science of the Earth 11–14, Magma – introducing igneous processes. Geo Supplies, Sheffield: ESTA.

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J3 How does rate of cooling

affect crystal size?

CHAPTER

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J4 Detecting how igneous

rocks were formed

CHAPTER

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1 Collect samples of four different kinds of igneous rocks – basalt, granite,pumice and obsidian.

2 Look carefully at each rock, looking especially carefully at how the grains (ifyou can see them) fit together. How is this different from the way the grainsfit together in a sedimentary rock?

3 Which of the four igneous rock samples has the smallest grains? Which hasthe largest grains?

4 The grains in these igneous rocks are crystals. Think back to what you foundout about how the rate of cooling affects crystal size. Which of the fourigneous rock samples do you think cooled most quickly? Which cooled mostslowly?

5 Magma cools quickly when it comes to the surface of the Earth. It coolsmore slowly if it stays beneath the surface. Which one of the four igneousrock samples do you think cooled beneath the surface of the Earth?

6 When a volcano erupts, the hot lava sometimes comes out as a foam, withbubbles in it. Which of the four igneous rock samples do you think wasformed when this kind of lava cooled?

You are going to look at pairs of rocks, a metamorphic rock and the type ofsedimentary rock from which it was formed.

1 Collect, or move to, the first pair of rocks. Make sure that you know whichis the sedimentary rock, and which is the metamorphic rock. (Your teachermay ask you to work this out for yourself!) Write their names in theheadings of a table like this:

2 Fill in the first two rows. Use a lens to help you to look closely at the rock.Remember the kinds of things that you used before when describing rocks,such as the size of the grains if you can see any.

3 Take small samples of each rock and weigh them in each hand to find outwhich seems to be the most dense. You could check whether you are rightusing a top pan balance and measuring cylinder. (If you are not sure howto do this, ask for help.)

4 Repeat steps 1 to 3 for the other pairs of rocks.

5 Try to find patterns in the differences between the sedimentary rocks andtheir corresponding metamorphic rocks. Write a short piece of advice tosomeone looking at an unknown rock, to help them to decide whether itis a sedimentary rock or a metamorphic rock.

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J5 Metamorphic rocksCHAPTER

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Feature Sedimentary rock Metamorphic rock

_____________________ _____________________

Colour

Appearance

Density (g per cm3)

Any other differences

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Sedimentary rocks often contain fossils. You are going to investigate whatmight happen to these fossils if the sedimentary rock is squashed and formsa metamorphic rock.

1 Collect some modelling clay and a shell. Press the shell deep into the clay,to make a shell-shaped impression. Take the shell out very carefully.

2 Now ‘metamorphose’ your clay ‘rock’ by squeezing it. Decide which way tosqueeze – you could squeeze from side to side, from top to bottom, ordiagonally.

Source: from Earth Science Teachers’ Association (1990) Science of the Earth 11–14, Hidden changes in the Earth. Geo

Supplies, Sheffield: ESTA.

Don’t overdo it – you still want to have a recognisable shell-shapedimpression in the clay.

J6 What happens to fossils

during metamorphism? (page 1)

CHAPTER

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From top to bottom

From side to side opposite each other

From side to side past each other

➤continued

3 Collect some plaster of Paris powder. Put no more than 1 cm depth ofwater into a container, and mix plaster of Paris into it to form a thick butstill runny white liquid.

4 Pour the liquid plaster into the shell-shaped impression in the clay. Leave itto set.

While it is setting, wash any plaster of Paris off anything it has got on – doit quickly before it sets hard!

5 When the plaster of Paris has set, take your ‘fossil’ out of the clay. Scratchyour initials on it.

6 Swap ‘fossils’ with another person. Can you work out which way the forceswere acting on their ‘rock’? Can they do the same for your fossil?

Source: adapted from ‘Detecting the distortion’ in ‘The Dynamic Rock Cycle’, pp. 10–11, available from

http://www.earthscienceeducation.com/handouts/ (accessed 5/12/02), based on Earth Science Teachers’ Association (1990)

Science of the Earth 11–14, Hidden changes in the Earth. Geo Supplies, Sheffield: ESTA.

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J6 What happens to fossils

during metamorphism? (page 2)

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CHAPTER

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You know how three different types of rocks are formed – sedimentary rocks, igneous rocks and metamorphic rocks.

The materials in one type of rock can eventually become part of a verydifferent rock. The flow diagram below begins to show how this can happen.It is called the rock cycle.

Use these words to complete the rock cycle flow diagram:

metamorphic rocks igneous rocks pressure and heatweathering, erosion and deposition melting melting

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J7 The rock cycleCHAPTER

WORKSHEET7

10


weathering, erosionand deposition

weathering,erosion

and deposition

sedimentaryrocks

cooling

magma

melting


1 Choose the best words to complete each of these sentences. You can use eachword once, more than once or not at all.

magma fossils hot wet igneous metamorphicsedimentary quickly lava larger smaller

a Rocks melt when they are very deep underground because it is extremely

............................................ .

b Liquid rock is called ............................................ when it is underground and

............................................ when it comes out onto the surface.

c Basalt and granite are examples of ............................................ rocks.

d Basalt has ............................................ crystals than granite because basalt

cools more ............................................ .

d Igneous rocks never contain ............................................ .

(7)2 Here are some processes that occur in the rock cycle.

A Repeated heating and cooling causes a rock in the desert to shatter.B Grains of sediment collect in a layer on the sea bed.C Layers of mudstone are squashed and squeezed to form slate.D Molten rock cools and solidifies under the surface of the Earth.E Grains of sand are deposited by a river, buried and then cemented

together.F A river carries away fragments from a shattered rock.G Lava flows out of a volcano and solidifies.

a Write down one letter that describes each of these processes:

erosion ............................................

weathering ............................................

(2)

b Which letters describe the formation of sedimentary rocks?

............................................ and ............................................

(2)

End of Unit test

The rock cycle

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407

c Which letters describe the formation of igneous rocks?

............................................ and ............................................

(2)

d Write the letter of the process that could form granite.

..............................................................................................................................

(1)e What is the name of the process described in C?

..............................................................................................................................

(1)3 A teacher carried out this demonstration to show what happens when

volcanoes erupt.

Source: from Tuke, M (1991) Earth Science Activities and Demonstrations. London: John Murray.

a Use your knowledge of particles to explain why the solid wax becomes a liquid when it is heated.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)



cold water

sand

red candlewax

wax beginning tomelt and rise

hot Bunsenflame

beaker


b When the hot liquid wax reaches the water surface, it spreads out and cools. In what ways is this similar to what happens when a volcano erupts?

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)c Volcanoes often erupt much more violently than this. Explain how a

violent eruption may lead to the formation of a rock called pumice.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)Go to the next page for question 4.



4 Diagram A shows a fossil. Diagrams B, C and D show some fossils that havebeen squashed.

a For each fossil, write the letter of the arrows that show the forces that squashed the rock.

fossil B ....................... fossil C ....................... fossil D .......................

(2)

b Name two types of rock in which the fossils might first have been formed.

..............................................................................................................................

(2)

Total marks: 25


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Extension question

5 This diagram shows a section through some rocks.

a Which is the very oldest rock shown in the diagram? Explain why you think this is the oldest rock.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)b Rock A is limestone. Suggest how you could test the rock to check that it

is limestone.

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(2)


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B

C

D

E

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c The rock in part X of the limestone looks different from Rock A. It is made of crystals packed tightly together, and it is very hard.i What is the name for this rock?

..........................................................................................................................

(1)ii Describe how this rock has probably been formed.

..........................................................................................................................

..........................................................................................................................

..........................................................................................................................

(2)iii What is the general name given to rocks that are formed in the way

you have described in ii?

.............................................................................................................................

(1)d i Describe one way in which you would expect Rocks E and F to differ

from each other, if you looked at them really closely.

............................................................................................................................

............................................................................................................................

(1)ii Explain why you would expect these rocks to differ in this way.

..........................................................................................................................

..........................................................................................................................

(1)




Text answers

1 a limestone, bottom, squashedb interlock, porous, cementc organisms

2 In a solid, particles are arranged in a regular pattern, close to each other andvibrating on the spot. As they are heated, the particles gain more kineticenergy and move more rapidly. So they lose their regular arrangement andbegin to move around, though still remaining in contact with each other.The solid has become a liquid.


b Cholera is caused by a bacterium. The bacteria are present in the faeces ofan infected person. If these bacteria get into drinking water, they can causeinfection in the person who drinks it. In Goma, after the eruption, watersupplies were disrupted so it was very likely that they could becomecontaminated with human excrement.


1 a moltenb magma, lavac igneous

2

3 a Rocks B and C are igneous rocks, while Rocks A and D are sedimentary rocks. A and D are made of grains that do not fit tightly together, while in B and C there are no obvious spaces between any visible grains. In addition, D contains fossils which no igneous rock can do.

b Rock B, because it has no visible crystals.c Rock C, because it has big crystals which means it cooled slowly.d Rock A, because this is the other sedimentary rock.e A sandstone, B obsidian, C granite, D limestone (or chalk).

The rock cycleC

HAPTER

10

ANSWERS

Sedimentary rocks Igneous rocks Metamorphic rockssandstone basalt slatelimestone granite marblechalk obsidianmudstone pumicerock salt


Worksheet answers

J7The rock cycle


1 a hotb magma; lavac igneousd smaller; quicklye fossils (7)

2 a F; A (2)b B; E (in either order) (2)c D; G (in either order) (2)d D (1)e metamorphism (1)

3 a Particles/molecules, gain energy (as they are heated); move faster/move more (not ‘begin to move’) (2)

b It is like lava cooling; which solidifies to form rock (e.g. basalt) (2)c Lava blown out; with gas bubbles in it; cools to form rock with air spaces

(2 max.)

Chapter 10 Answers



weathering,erosion

and deposition

sedimentaryrocks

metamorphicrocks

cooling

pressure and heat

igneous rocks

magma

melting

melting

melting


4 a B, R; C, P; D, Q (half mark for each one correct, round up; 2)b Any two named sedimentary rocks (2)

Total marks: 25

Extension answers

5 a B; it is the deepest layer (except for the igneous rock which has forced its way through it) (2)

b Add (hydrochloric) acid; if it fizzes it is limestone (2)c i marble (1)

ii hot magma flowed through the limestone; the heat made the crystals alter (2)

iii metamorphic (1)d i E would have smaller crystals than F (1)

ii E cooled more quickly than F (1)Total marks for Extension: 10



Chapter 10 Answers

Pupils should be familiar with the following ideas:• That different living things live in different habitats• That animals and plants are adapted to survive in a habitat• That feeding relationships can be represented by food chains and food webs• That organisms can be classified into animals and plants

11 Ecological relationships

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Starting points


AnnelidArthropodCnidarianCommunityConiferConsumer

CrustaceanEcologistFernFlowering plantHabitatInsect

InvertebrateMolluscMossPopulationProducer

Pyramid ofnumbers

QuadratSamplingVertebrate

In this topic pupils should learn:• to study a habitat in detail• to identify organisms and compare sizes of populations• how to model feeding relationships quantitatively• that living things within a community influence each other and are affected by

the environment• to model consequences of environmental changes within a habitat• how to sample• how to collect, present and interpret data, and how to use data to make

predictions• how to undertake fieldwork to collect information about organisms in a habitat

Learning checklist

Links

9HRS

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Unit Title7C Environment and Feeding Relationships7D Variation and Classification8C Microbes and Disease9C Plants and Photosynthesis9D Plants for Food9G Environmental Chemistry


CH A P T E R

1 1

T I M I N G

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Cross-curricular linksFieldwork is also covered in Unit 7 ‘Rivers – a fieldwork approach’ in thegeography scheme of work.

LiteracyThere is a literacy activity on hedgehogs and how introducing them to the OuterHebrides upset the ecosystem there.

ICTThere are links with Unit 3 ‘Processing text and images’ and Unit 7 ‘Measuringphysical data’ in the ICT scheme of work, with opportunities for presentations on,and measurements in, the environment.


?b

ca

ICT

Most pupils

Scientific enquiry• Suggest what data should be collected to investigate a habitat• Choose appropriate apparatus and techniques to make measurements and

observations• Use a sampling technique to collect data to compare populations in habitats• Use ICT to collect, store and present information in a variety of waysLife processes and living things• Classify some plant specimens into the main taxonomic groups of plants• Identify and name organisms found in a particular habitat• Explain how organisms are adapted to the environmental conditions and how

adaptations help survival• Relate the abundance and distribution of organisms to the resources available

within a habitat and begin to represent this using pyramids of numbers

Pupils who have not made so much progressScientific enquiry• Collect data to investigate a question about a habitat using appropriate

apparatus and techniques• Use ICT to collect, store and present informationLife processes and living things• Name some organisms found in a habitat• Describe how organisms are adapted to environment conditions• Recognise that the abundance and distribution of organisms are different in

different habitats

Pupils who have progressed furtherScientific enquiry• Plan how to collect reliable data, taking into account the fact that variables

cannot readily be controlledLife processes and living things• Explain how pyramids of numbers represent feeding relationships in a habitat

Learning outcomes


418


The opening of this chapter focuses on an ecologist. You may like to discuss withpupils what ecologists do, perhaps making the point that before we can conserveanything (such a tropical rainforest or a flowery meadow) we need to know whatlives there and how the different living things interact. This could then lead in tothe work on classification and, later, to sampling and investigating populations orcommunities in a habitat.

Classifying animals and plantsThis section builds on work covered in Chapter 11 in Year 7 Book 1, Variation andclassification. You may like briefly to recap this work before pupils tackle questions1, 2 and 3 on pages 148–149. Here, photographs are used instead of the simpleline drawings in Book 1. Worksheet K1, Classifying animals, could be done eitherbefore or after the questions in the Pupil Book.

Plant classification is likely to be new to most pupils. Worksheet K2, Four groupsof plants, asks pupils to work out the major obvious differences between mosses,ferns, conifers and flowering plants. If at all possible, provide fresh specimens forthem to look at. Photographs and reference books could also be used.Worksheet K3, Classifying plants, and the section on ‘Different kinds of plants’ onpage 150 of the Pupil Book take this a little further. It is probably best not tointroduce too many new terms here – for example, ‘vascular bundles’, ‘spores’ or‘rhizoids’. Do, though, make clear that the little things growing from the bases ofmoss plants are not true ‘roots’. The main target at this stage is to help pupils torecognise different types of plants when they find them during their work outside.

Communities and populationsThe text in the Pupil Book, and question 4 on page 150, briefly revise work donein Year 7 on adaptation. This then leads on to the idea that different kinds ofliving things are found in different habitats, and the terms ‘community’ and‘population’ are introduced. The term ‘ecosystem’ has been deliberately avoided,but you could introduce this here if you feel the class is ready for it.

Although most pupils will have done some simple practical ecology work, theywill probably not have done anything quantitative. They should already have metthe idea of ‘sampling’, and here they are asked to think about how you couldsample a habitat to find out what lives there, and how big the populations are.Worksheet K4, Sampling a population, is intended as a preparatory activity beforefieldwork is done. (Note that although ‘tacks’ are suggested on the worksheet,you could use any small objects that are readily extracted from sand with amagnet, and may prefer not to use something as sharp as tacks.) After pupilshave finished this worksheet, you could discuss with them how big a sample youneed to take to get a reliable result. There is a happy medium to be foundbetween counting every single organism (impossibly time-consuming) andcounting a very small sample of them (which may give very unreliable results).

If at all possible, it is recommended that pupils work outside at this stage. Exactlywhat you do will depend on where you can safely take them and supervise them.This does not have to be anywhere special – an area of grass in the schoolgrounds is perfectly adequate. However, going somewhere different obviously hasan excitement about it that you will not get on the football pitch.

If you do take pupils out of the school grounds, then of course school policyneeds to be closely followed, and adequate preparations made to ensure that youhave plenty of adults to help with supervision and that all safety aspects havebeen taken into account.


419

There is much to be said for taking a whole day to do field work, or at least awhole morning or afternoon. Identifying organisms and collecting data is time-consuming, and it is much more satisfying for everyone if they can ‘finish’ theirwork in one go, rather than having a lot of little sessions on it. You can speed upthe identification side of things by providing identification sheets that pupils cancarry round with them. This requires considerable preparation – but if you have aflat-bed scanner then you can easily make professional quality colour ‘photographs’of plants simply by placing a specimen on the scanner, producing a computerimage that can be printed out. Make sure that you do these scans at the same timeof year that the pupils will be looking for the plants.

A possible day’s work in the school grounds, looking at grassland habitats, couldfollow a sequence along these lines:

• Introduction to the habitats to be studied, for example a games pitch and anarea of longer grass. Walk around them and talk about what might live there andwhat is different about them.

• Introduction to the animals and plants that pupils may find. Make sure that eachgroup can identify most of the plants and some of the animals in the habitats.

• Mark out ‘axes’ in each area, and do quadrat work in each (see below for whatthis could entail).

• Measure or find out about several environmental factors in each habitat, forexample light intensity, soil pH, soil moisture content, temperature, grass height,frequency of being walked on, frequency of mowing.

• Record results together, and discuss findings.

Worksheet K5, Sampling organisms in a grassy habitat, and Worksheet K6,Comparing the daisy populations in two habitats, describe one kind of investigationthat could be done in the school grounds. You could easily adapt these worksheetsfor other habitats; for example, comparing the limpet population in the middleshore and upper shore, or comparing the freshwater shrimp population in a slow-moving or fast-running stream (in the latter case, you would need to use anothersampling method, such as kick-sampling, rather than using quadrats). Anotherpossibility would be to make quantitative comparisons between communities in twoareas, or to place quadrats along a transect to investigate changes in communitiesacross a change in habitat – but it is probably best not to be too ambitious at thisstage. Dealing with large amounts of data is cumbersome and time-consumingwhen done properly. It is better to do a small and closely focused investigationwell, rather than to attempt something larger that can be done only superficially.Whatever you do, keep all the data to add to whatever is collected in subsequentyears – you might then be able to look at changes over time.

If you use quadrats, it is very strongly recommended that you use the randomnumber method of placing them, rather than throwing. Some calculators are ableto generate random numbers, or you can use published random number tables.Thrown quadrats can be dangerous – as well having a mysterious tendency neverto land in a bramble patch or stinging nettles.

If the populations of the species are found to be different in the two habitatsinvestigated, then pupils could try to suggest reasons for these differences. Theyshould be encouraged to see that they cannot possibly know what these reasonsare, because there are so many variables. This is a classic difficulty with ecologicalstudies. They can, however, use their data to put forward suggestions, and youmight like to discuss with them how these could be investigated in a controlledenvironment (a laboratory). The extension question in the End of Unit test revisitsthis idea.



How organisms depend on each otherThis section builds on work on food webs and food chains covered in Year 7 PupilBook 1, Chapter 8, Environment and feeding relationships. Question 8 on page 154of Pupil Book 2 will help to remind pupils of this work, and also the meaning ofthe new word community that they have recently learnt.

The concepts involved in drawing food chains and food webs are now takenfurther, with the introduction of pyramids of numbers. It is recommended that thisbe dealt with very simply at this stage, with no mention yet of trophic levels,pyramids of biomass or energy, or even of the reasons for the shape of thepyramids in terms of energy losses. These seemingly simple concepts are actuallyhighly complex, and pupils much older than this often acquire deeply flawedunderstandings of them. For example, pupils will often state that you get moreenergy from eating vegetables than from eating meat, because plants are nearerthe beginning of a food chain. Most pupils will readily see that you need a largepopulation of rabbits to feed one fox, and this is a good level to stay at. Energylosses between trophic levels can be explained at KS4.

Some texts show pyramids drawn as a triangle, rather than as rectangles piled ontop of one another. This is not good practice. A pyramid of numbers is a type ofgraph. If drawn quantitatively, the area of each box should represent the numberof organisms at that level. Obviously, it is not easy to calculate the area of the‘boxes’ in a triangle.

Pupils are asked to consider the various ways, other than eating or being eaten,that organisms depend on each other. The Pupil Book gives several examples, butpupils may be able to think of others. This can then lead into the idea of‘balance’ in a community, in which a change in the population of one species canhave significant effects on many others. However, they should appreciate that it isalmost impossible to predict what these changes may be, and this needs to beborne in mind if pupils try to suggest what might happen to the organisms in afood web if one of them disappears. It can only be educated guesswork.

Another often over-simplified idea is the relationship between populations ofpredators and their prey. Question 3 in the end of chapter questions looks at this,and pupils will probably be able to answer this using their own common sense.However, close relationships such as this between predator and prey populationsare exceedingly rare, at least partly because most predators have many differentprey species, most prey have many different predators, and several other factorsaffect both of their populations.

Literacy activityThe literacy activity, ‘Killer hedgehogs’, provides a real example of the problemscaused by the introduction of an alien species. You could try reading this aloudwith the class, and then discussing question a together, encouraging them to thinkcarefully about what evidence would be required and how it might be collected.Question b could then be answered in groups or individually. It could beenjoyable to have a lesson in which pupils speak at the ‘public meeting’ to decidewhat is to be done.


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Classifying animals and plantsYou should be able to find fresh material for the Worksheet K2, Four groups ofplants, activity at any time of year. However, spring and summer are likely toprovide a wider range than winter.

Be aware that it is an offence to remove some plants from their habitats. Try theschool grounds first, or a garden.

Flowering plants can be found almost everywhere. It will be easiest for pupils toclassify them if there are flowers present. You could perhaps also provide somewith fruits, or even with flowers and fruits on the same plant – small weeds suchas groundsel and shepherd’s purse are ideal for this, and their small size makes itpossible to use the whole plant, roots included. Grasses with flowers could beprovided, but be aware of potential problems for pupils with hay fever. Twigsfrom trees with flowers, such as apple, oak, pussy willow or horse chestnut,would also be very good, as would parts of vegetable plants – for example, partsof a runner bean plant or courgette plant, with flowers. You could also supplysome that do not have flowers, to give pupils the chance to work out what theyare when the most obvious clue is not present.

Do not supply anything that you do not recognise and know to be safe, as thereare many poisonous flowering plants.

Conifers: use small twigs or branches broken from a tree, and try to make surethere are cones present. Pine, spruce and larch are likely to be the easiest to find.Yew is a conifer, but do not use it as some parts are poisonous. It is alsorecommended that you do not use specimens where there is a lot of resin on thecones, as this is very difficult to remove from skin or clothing.

Ferns can be found growing in a wide variety of places – try shady pathways,under trees, in shady corners of gardens. If all else fails, buy some pot-grownferns from a garden centre. Try to find some with fronds that are just unfurling,and some where there are clearly visible groups of brown spores on theundersides of some of the fronds.

Mosses can be found in almost any damp place. Look at the base of damp walls,on tree trunks, on the ground in woodland, on unweeded soil in shady parts of agarden, between grass in areas such as lawns and games pitches. Try to find somewith spore cases. Provide pupils with complete plants, including the little rhizoidsthat attach them to the ground.

Communities and populationsDaisies are suggested for Worksheet K5, Sampling organisms in a grassy habitat,and Worksheet K6, Comparing the daisy populations in two habitats, but they maynot be the ideal plant to use in the area you are able to use for this activity.Choose a species that is likely to be found in at least half the quadrats that thepupils put down, and that is easy to identify. The species must also be easy tocount, so the individual plants must be obviously separate from one another.Grass or clover, for example, would not do.

The lengths of the ‘axes’ that the pupils will use for placing their quadrats will beat least partly determined by the area you have available to study. You may beable to arrange things so that each group has a different pair of axes, or it may



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Scientific Enquiry

2a, 2d, 2e, 2f, 2g, 2i

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4b, 5c, 5d, 5e

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Physical Processes


be easier for two or even three groups to use the same pair. You can use tapemeasures marked off in metres and centimetres, or just two long lengths of string– if the latter, then pupils count paces rather than measuring. To place a quadrat,pupils find a pair of random numbers, then use the first one to tell them howmany paces to walk along the x-axis. They then use the second one to tell themhow many paces to walk away from the x-axis, parallel to the y-axis. This givesthem the position of the quadrat.

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What I have learnt

Ecological relationships


SamplingFlowering plant

Community

Ecologist

Annelid

Crustacean

Quadrat

Habitat

Population

Arthropod

Conifer

Moss

Fern

Cnidarian

Consumer

Insect

Invertebrate

Vertebrate

Producer

Pyramid of numbers

Mollusc


• I can classify animals into differentgroups

• I can classify plants into mosses,ferns, conifers and flowering plants

• I know that every organism isadapted to live in a particularenvironment

• I know that a community is all theliving organisms in a habitat

• I know that a population is all theorganisms of one species in ahabitat

• I know how to use quadrats tosample a habitat

• I can plan and carry out aninvestigation to comparepopulations in two habitats

• I know that environmental factorsin a habitat affect the numbers anddistribution of organisms in it

• I know that organisms in acommunity depend on each otherin many ways

• I know how pyramids of numberscan be used to represent numbersof organisms in a food chain

• I know why pyramids of numberscan be different shapes

• I know that making a small changein a community can have a verylarge effect on it

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Lesson Focus Pupil Book 2 pp. 148–149Classification of vertebrates and invertebrates, and of arthropods

Expectations

Most Pupils Can classify animals into vertebrates or invertebrates; invertebratesinto one of four groups; and arthropods into one of four groups.

Less Able Pupils Can classify animals into vertebrates or invertebrates, andinvertebrates into one of several groups.

More Able Pupils All the above, plus can deduce characteristic features of particulargroups by looking at a range of specimens or images.



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Live specimensPhotographs and drawings of a range ofvertebrates and invertebrates, and ofinsects, crustacea, millipedes andcentipedes, and spiders. (These can bearranged around the room and givennumbers or letters, before the classbegins)

Information sheetFor classwork and homework

Worksheet K1 Classifying animalsFor homework

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10 In and register. Pupils begin to think about why ecologists may need to Starter. Introduce the term ‘ecology’, with reference to the photograph on classify living things.page 148 in the Pupil Book, and so lead in to the need for classification. With They revise their knowledge of the classification of vertebrates the class, talk through questions 1 and 2 on pages 148–149 of the Pupil Book. and invertebrates.

15 Development. Distribute the Information sheet and ask pupils to move around the Less able pupils can be provided with a sheet Pupils reinforce knowledge of the classification of vertebrates room and look at the specimens, photos and drawings provided. Classify each one listing each animal’s name, letter or number, to and invertebrates, and apply their knowledge to ‘new’ as one of the five types of vertebrate, or as a mollusc, arthropod, annelid or cnidarian. be filled in. animals.

10 Ask pupils to swap their lists with a friend who will mark their work. Run Pupils learn of any mistakes in their classifications and correct through the correct classifications, and collect scores for everyone. Discuss any these.‘problem’ animals that were difficult to classify.

10 With reference to specimens, and to the photographs on page 149 in the Pupil Less able pupils will be able to classify most Pupils deduce the characteristic features of four groups of Book, talk through question 3. Draw out the characteristic features of insects, specimens of arthropods into one of these four arthropods. crustaceans, millipedes and centipedes, and spiders. groups, but may forget that they are all arthropods.

5 Plenary. Distribute Worksheet K1 Classifying animals, and ask pupils to complete this for homework.

Homework: Worksheet K1, using the Information sheet.


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Lesson Focus Pupil Book 2 p. 150Classifying plants

Expectations

Most Pupils Know the distinguishing features of flowering plants, conifers, fernsand mosses and are able to observe and record these accurately.

Less Able Pupils Know that plants can be classified into different groups, and areable to classify some plants and to observe some of theirdistinguishing features.

More Able Pupils All the above, plus can use observations to suggest distinguishingfeatures of these four groups of plants.



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Worksheet K2 Four groups of plantsFresh specimens of complete floweringplants, ferns and mossesSmall branches from conifers with conesPhotographs and drawings of a range ofplants belonging to these four groupsArrange around the room, with handlenses and binocular microscopes ifappropriate

Worksheet K3 Classifying plantsFor homework

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10 In and register. More able pupils will be able to suggest Pupils begin to recognise the characteristic features of Starter. With the class, look at the diagrams of flowering plants, conifers, ferns distinguishing features, using their general flowering plants, conifers, ferns and mosses.and mosses on page 150 of the Pupil Book. Discuss with them where they might knowledge as well as the information on the expect to find these kinds of plants, and some of their more obvious diagrams.distinguishing features.

20 Development. Distribute Worksheet K2 Four groups of plants. Ask pupils to Less able pupils will need considerable support to Pupils learn to observe and record carefully. They reinforce move around the room and use the specimens provided to help them to enable them to observe and record all of the their understanding of the distinguishing features of these four complete the table on the worksheet. features in the table in the time available. groups of plants.

15 Settle pupils in mixed ability groups. Place an image of a moss on an OHP and Less able pupils will be helped by the more able Each pupil has a correct record of the features of these four ask for suggestions about the appropriate response in the first box of the table. to correct and complete their tables. groups of plants.(‘Comparative’ boxes will have to be left until later in the discussion.) Discuss this with them and allow them to make alterations to their tables if necessary. Repeat with the other boxes for mosses, and then with each of the other three types of plants.

5 Plenary. Distribute Worksheet K3 Classifying plants and ask pupils to complete this for homework.

Homework: Worksheet K3.


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Lesson Focus Pupil Book 2 pp. 150–152Communities and populations

ExpectationsMost Pupils Know the meanings of the terms habitat, adaptation, community

and population. Understand how sampling may be used toestimate population size and how sample size may affect theaccuracy of their estimate.

Less Able Pupils Know the meanings of the terms habitat, adaptation, communityand population. Use sampling to estimate population size.

More Able Pupils All the above, plus appreciate that sampling can never give anentirely accurate result when estimating population size.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Calculating estimated total numbers from a sample.ICT:


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Worksheet K4 Sampling a populationPer group:A fairly large plastic tray filled with sandAt least 30 steel tacks or ball bearings(more if possible)Square wire mesh which can be placedon the trays to divide them into at least20 squares (up to 30 if possible)Bar magnets strong enough to pick up thetacks through sand

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10 In and register. Pupils revise their knowledge of the terms ‘habitat’ and Starter. Ask pupils to tell you the meaning of the terms ‘habitat’ and ‘adaptation’, and their understanding that organisms are ‘adaptation’. Discuss with them the answers to question 4 on page 150 of the adapted to their habitats.Pupil Book.

5 Development. With reference to the diagrams on page 151 of the Pupil Book, Pupils learn the meaning of the term ‘community’.explain the meaning of the term ‘community’. Discuss the answers to question 5 on page 151 of the Pupil Book.

10 With reference to the upper drawing on page 152 of the Pupil Book, explain the More able pupils will have more realistic Pupils learn the meaning of the term ‘population’.meaning of the term ‘population’. Ask pupils how they might try to find out the suggestions to make about how population size They begin to think about the difficulties of estimating number of organisms in a population of woodlice (or some other organism with might be estimated. population numbers.which they are familiar) in a garden.

20 Distribute Worksheet K4 Sampling a population. Arrange pupils into Pupils are introduced to the idea of sampling in order to pairs of groups, and ask them to carry out this activity. estimate population size.

5 Plenary. Settle pupils. Ensure each person has a record of results, and collectsthe information from their partner group about the number of tacks.

Homework: Write up the activity on Worksheet K4, including the answer to question 7.


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Lesson Focus Pupil Book 2 pp. 152–153Using random sampling to estimate population size

Expectations

Most Pupils Use a quadrat to estimate the population size of daisies in a grassyarea; know how to use random numbers to place the quadratrandomly.

Less Able Pupils Use a randomly placed quadrat to count the numbers of daisies insample squares within a grassy area.

More Able Pupils All the above, plus understand some of the limitations of thismethod of estimating population size.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Calculating means.CT:


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Worksheet K5 Sampling organisms ina grassy habitatClipboards (one per pupil)Per group:A quadrat with sides of 0.5 mTable of random numbers or a calculatorthat can generate themLarge tape measure or lengths of string toact as ‘axes’ of the study area

Worksheet K6 Comparing the daisypopulations in two habitatsFor homework

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10 In and register. Pupils know what a quadrat is and how it can be used to Starter. Distribute Worksheet K5 Sampling organisms in a grassy habitat. sample populations.Explain what pupils are going to do and where. Emphasise safety: set boundaries as to where they can go and rules for behaviour when outside.Arrange pupils into groups, and distribute a quadrat, random number table or calculator, two lengths of string or measuring tapes to each group. Ask each pupil to collect a clipboard onto which they fix their worksheet.

25 Development. Take pupils to the study area outside and ensure each pupil can More able pupils will be quicker to understand Pupils use a quadrat to sample plant populations. They begin identify the type of plant they are counting. Show them how to use string or the use of axes and random numbers to place to look closely at plant communities and how individuals are tapes as ‘axes’ and random numbers as coordinates to place their quadrats quadrats, and so will take the lead in this part of distributed within them.(by measuring or pacing). the task.Assign each group to an area and ask them to complete the task on the worksheet.

10 Either return indoors, or settle pupils in the outdoor study area (depending on Less able pupils may not have a complete set of Pupils consider how results from a sample can be used to weather and pupil behaviour) to discuss their results and the answers to results, and can now collect these from other estimate total population size. They appreciate the balance questions 1 and 2 on Worksheet K5. Ensure each pupil has a complete set of members of the group. needed between taking as large a sample as possible and results. spending a reasonable amount of time.Indoors, if time allows, discuss answers to questions 6 and 7 on page 153 of the Pupil Book.

5 Plenary. Distribute Worksheet K6 Comparing the daisy populations in two habitats. Outline the task, discussing suitable habitats. You may wish to tell pupils which habitats to use, or let them decide for themselves. Set homework.

Homework: Plan the investigation on Worksheet K6, ready to carry it out next lesson.


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Lesson Focus Pupil Book 2 pp. 152–153Carrying out a planned investigation into differences in populations in two areas

ExpectationsMost Pupils Use quadrats to estimate populations in two areas, and make

suggestions about reasons for any differences found and how atleast one of these could be tested.

Less Able Pupils Use quadrats to estimate populations in two areas, and make atleast one suggestion about a reason for any differences found.

More Able Pupils All the above, plus appreciate that any apparent differences foundmay not be ‘real’, and also put forward a range of suggestionsabout reasons for these differences, and ways to test suggestions.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Calculating means and comparing two sets of numerical results.ICT:


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As last lesson, plus equipment formeasuring environmental factors whichcan be ‘lent’ to groups as required, forexample thermometer, light meter, pHmeter, hygrometer

Worksheet K6 Comparing the daisypopulations in two habitats

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10 In and register, asking pupils to sit in the groups that they worked in last lesson. More able pupils will take the lead in deciding Pupils work cooperatively to decide on the best way of Starter. Ask pupils to get their copies of Worksheet K6 Comparing the daisy exactly what plan to follow. Less able pupils carrying out their investigation.populations in two habitats and their plans for this investigation. Ask groups will be encouraged to make some contribution.to discuss these plans and to decide on what they are going to do. Move between groups and check that each is sufficiently organised to be allowed to proceed.Allocate equipment to groups as last lesson.Emphasise safety as last lesson.

25 Development. Move outside, and ask groups to carry out their planned Pupils reinforce their knowledge of using a quadrat to investigations. estimate population size. They make quantitative comparisons Move between groups and, as they begin to approach a complete set of results, between populations in two areas.ask if they would like to use equipment to measure an environmental factor.

10 Either return indoors, or settle pupils in the outdoor study area (depending on Less able pupils will find it difficult to question Pupils increase their appreciation of the relationship between weather and pupil behaviour) to discuss their results. Ask: ‘How reliable do you their results. They may put forward one sample size and reliability of results. They put forward think your results are?’, ‘What could you do to improve their reliability?’, suggestion to explain differences in the two areas, hypotheses to explain the pattern of their results, and consider ‘If you found differences, what do you think might have caused them?’, and see this as being ‘the answer’. More able how they could test these hypotheses.‘How could you investigate this?’ pupils will pose more questions about the

reliability of their results, and will put forward a number of hypotheses to explain any differences they found in the two areas sampled, recognising that these are no more than suggestions.

5 Plenary. Ensure each pupil has a complete set of results, and set homework.

Homework: Write up the investigation on Worksheet K6.


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Lesson Focus Pupil Book 2 pp. 154–155Pyramids of numbers

Expectations

Most Pupils Can draw qualitative pyramids of numbers to match a wide rangeof food chains.

Less Able Pupils Can draw qualitative pyramids of numbers to match some foodchains.

More Able Pupils All the above, plus can make realistic suggestions about ways ofestimating population sizes of a range of organisms.



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10 In and register. More able pupils will remember these terms and Pupils revise the meanings of the terms producer, consumerStarter. Ask: What is a community? How might the organisms in a community volunteer information. and community. They began to think about interactions depend on each other? Help pupils to remember what they know about food between organisms in a community.chains and food webs. Revise the meanings of the terms ‘producer’ and ‘consumer’.

10 Development. Ask pupils to answer question 8 on page 154 of the Pupil Book, More able pupils may finish this quickly, and can Pupils reinforce their knowledge of food chains and food in their workbooks. use any available time to illustrate their food chain webs.

or food web.

10 With reference to the food chain diagram on page 154 of the Pupil Book, discuss Pupils are introduced to the idea of pyramids of numbers.numbers of organisms at each step in a food chain and hence the idea of pyramids of numbers.

10 Ask pupils to answer question 9 on page 155 of the Pupil Book in their Pupils consolidate their understanding of pyramids of workbooks. In each case, they should write out the food chain and then draw numbers, and apply their understanding to different food the pyramid next to it, labelling each box in the pyramid. chains.

10 Plenary. Ask pupils to suggest three or four food chains beginning with daisies Pupils use their knowledge of estimating population sizes to (or the plant which they investigated last lesson) in the area they have think about how data could be collected to draw pyramids of studied. Ask for suggestions about how they might try to estimate the population numbers.sizes of the other organisms in these food chains, in order to collect data for drawing pyramids of numbers.



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Lesson Focus Pupil Book 2 pp. 155–157Interrelationships within a community

ExpectationsMost Pupils Understand that there are many ways in which organisms in a

community interact, and describe some of these. Understand howand why predator and prey numbers may show similar patterns.Put forward ideas about how to investigate cause and effect in anecological situation, and how to deal with an environmentalproblem.

Less Able Pupils Outline some of the ways in which organisms in a communityinteract. Appreciate why predator and prey numbers may showsimilar patterns. Suggest ways of dealing with an environmentalproblem.

More Able Pupils All the above, plus appreciate the great difficulties in determiningcause and effect in an environmental situation, and in correctingimbalances in a community caused by introduction of an ‘alien’species.



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Stimulus material, e.g. video clips,photographs, to support the literacyactivity ‘Killer hedgehogs’, and videoclips, photographs of bird breedingcolonies on islands

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10 In and register. More able pupils will think of a wide range of Pupils begin to appreciate the many ways in which organisms Starter. With reference to the cartoons on page 155 of the Pupil Book, ask ways in which organisms interact. within a community interact. They understand how a change pupils to suggest ways, other than eating and being eaten, that organisms in the population of one species may have wide-ranging in a community may depend on and interact with each other. effects on other species.Discuss what can happen if humans remove a species from, or introduce a new organism to, a community, with reference to the photograph on page 156.

15 Development. Ask pupils to answer question 3 on page 159 of the Pupil Book Less able pupils will need to be helped with this Pupils understand how changes in population numbers of in their workbooks. as they work. predator and prey can affect each other.

20 Ask one or two pupils to read aloud the text of the literacy activity on page Pupils apply their knowledge of interrelationships to a 157 of the Pupil Book, ‘Killer hedgehogs’. complex situation, and consider how an ecological problem Ask pupils if they have seen hedgehogs and, if so, to describe their behaviour. may be tackled.If available, show video clips or photographs of hedgehogs moving around and feeding, and of bird breeding colonies on islands.Discuss questions a and b with the class.

5 Plenary. Explain and set homework.

Homework: Using question b as a basis, prepare a short statement or presentation to make at a public meeting to discuss what should be done about the hedgehogs in the Outer Hebrides.


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Lesson Focus Pupil Book 2 Chapter 11Debate on solving an environmental problemEnd of Unit test

ExpectationsMost Pupils Demonstrate secure knowledge and understanding of plant and

animal classification, sampling populations and communities, andinterrelationships between organisms.

Less Able Pupils Demonstrate some knowledge and understanding of plant andanimal classification, sampling populations and communities andinterrelationships between organisms.

More Able Pupils All of the above, plus plan an investigation into a possiblerelationship between an environmental factor and the distributionof freshwater shrimps.



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20 In and register. Less able pupils will need strong encouragement Pupils become involved in the difficulties of solving a problem Set up and chair (or ask a competent pupil to chair) a ‘public meeting’ or to join in the debate. caused by the introduction of an alien animal, and understand debate on what to do about the ‘killer hedgehogs’. that there is no easy solution and that there may therefore be

a range of views held by different people.

30 Distribute End of Unit test and ask pupils to complete this. More able pupils will answer more questions Pupils consolidate knowledge and understanding bycorrectly and will attempt the extension question. completing the End of Unit test.



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Classifying invertebratesInvertebrates are animals that do not have backbones.

Here are the characteristic features of some of the main groups ofinvertebrates.

Classifying arthropodsArthropods are invertebrates with jointed legs.

Here are the characteristic features of some of the main groups ofarthropods.

Information sheetCHAPTER

11


Group Characteristic features Examples

molluscs soft body, with a 'foot' that it slugs, snails, limpets,uses to move along; often has mussels, octopuses anda shell; no segments squids

annelids long, worm-shaped body made earthworms, leechesup of many ringed segments; often has tiny stiff ‘hairs’ onthe underside

cnidarians circular, soft body, usually with jellyfish, sea anemones,tentacles; no segments coral animals

arthropods body covered with a hard insects, spiders, scorpions,skeleton; made up of many millipedes, centipedes,segments; have jointed legs crabs, woodlice

Group Characteristic features Examples

insects six jointed legs; usually two butterflies, flies, bugs,pairs of wings; body divided bees and wasps,into head, thorax and dragonflies, cockroaches,abdomen; one pair of antennae grasshoppers, fleas

arachnids eight jointed legs; body divided spiders, scorpions, mitesinto a ‘head-thorax’ andabdomen; no antennae

crustaceans more than eight jointed legs; crabs, lobsters, woodlice,body divided into a water fleas‘head-thorax’ and abdomen;two pairs of antennae

myriapods many pairs of jointed legs; millipedes, centipedesbody divided into a head andmany segments; one pair ofantennae


➤continued

The diagram on the next page shows how the different kinds of animals areclassified.

In each of the boxes, write in at least one feature that would help you toidentify an animal in that group.

If you have time, make a small drawing of an appropriate animal next toeach box.

UN I T

K1 Classifying animals (page 1)

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animals

vertebrates invertebrates

mammals birds reptiles fish amphibians molluscs arthropods annelids cnidarians

crustaceans insects myriapodsarachnids


UN I T

K2 Four groups of plantsCHAPTER

WORKSHEET2

11

Look really carefully at at least one example of each of these kinds of plants:

• a flowering plant• a conifer• a fern• a moss

Copy and complete this table. You may need to ask, or look up, the answers tosome of the questions if you cannot see them on the plants themselves.

Moss Fern Conifer Flowering plant

Does it have leaves?

If so, are the leavesneedles?

Do the leaves havelots of veins?

Which has the thickestand which has thethinnest leaves?

What are the differencesbetween the top and thebottom of the leaves?

Does it have flowers?

Does it have cones?

Does it have strong roots?

What other differencescan you see betweenthese plants?


Classify each of these plants as either:

• a moss• a fern• a conifer• a flowering plant

UN I T

K3 Classifying plantsCHAPTER

WORKSHEET3

11

a

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You are going to try to find out the number of ‘organisms’ in a populationof tacks, by sampling just part of it.

Your group will need to join forces with another group for this activity.

1 Collect some steel tacks and a tray of sand. Count out a number of tacksand write down (secretly) how many you have. Bury them all in the sand.

2 Swap your tray of buried tacks with the other group’s tray.

3 Place some wire mesh over the tray, so that the sand is marked out intolots of squares.

4 Using a magnet, find and remove all the tacks in five squares. Count them,and then fill in the first two columns in this table. Then calculate theprobable number of tacks in the whole tray. (Ask for help if you are notsure how to do this.)

5 Now collect all the tacks in another five squares, and count them. Fill inthis table.

6 Repeat step 4 for 15 squares and for 20 squares.

7 Now find out from the other group how many tacks they actually buried.How close were you? Did you get better results when you sampled moresquares?

K4 Sampling a populationCHAPTER

WORKSHEET4

11

Total number of Number of tacks Estimated number of tackssquares in the grid found in 5 squares in the whole tray

Total number of Number of tacks Estimated number of tackssquares in the grid found in 10 squares in the whole tray


You can use quadrats to find out how many of a particular kind of plant livein the habitat. For example, this is how you could estimate the population ofdaisies in the habitat.

1 Use a quadrat with sides of 0.5 m.2 Pretend that two sides of the area you are studying are the axes of a graph.3 Use random numbers (from a book, or from a calculator) to decide where

to put the quadrat.

4 Count the number of daisy plants inside the quadrat. Record it in a tablelike this:

5 Now use another pair of random numbers to decide where to put thequadrat next. Count the number of daisy plants in it, and write this in yourtable.

6 Carry on doing this until you have counted daisies in 10 quadrats.7 Calculate the average (mean) number of daisies in each quadrat. (Ask for

help if you are not sure how to do this.)

K5 Sampling organisms in a

grassy habitat11

CHAPTER

WORKSHEET5

Quadrat 1 2 3 4 5 6 7 8 9 10

Number ofdaisy plants

Two paces from'start' then four

paces out

The next quadrat is sevenfrom start and five out

2 paces

Start

Quadrat here

4 paces out

1 How could you use your information to estimate the totalnumber of daisies in the whole habitat?

2 Do you think 10 quadrats was a suitable number to use?Would fewer have been better? Would more have beenbetter? Explain why you think this.Q

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You are going to plan and carry out an investigation to find out the answersto this question:

1 Is the population size of daisies different in two different grassy habitats?

If you find out that the populations are different, then you can also try toanswer the question:

2 What could be the reasons for the difference in the two populations?

Choose two habitats that are similar to one another, but not exactly thesame. For example, you could compare:

• an area of regularly mown grass (a lawn or a football pitch) and anotherarea where the grass is allowed to grow a bit longer; or

• a grassy area in the sun and another grassy area in the shade; or• a grassy area where the ground is very dry and another grassy area where

the ground is wetter.

You can use quadrats to answer question 1. Think carefully about exactlywhat you will do. You might be able to make use of the results you havealready got from Worksheet K5, Sampling organisms in a grassy habitat,which would save you quite a lot of work.

To answer question 2, you will have to be a bit of a detective. Think aboutanything that might possibly be different between the two habitats. Thencheck out your ideas. For example, you might want to try measuring:

• the temperature;• the pH of the soil;• the light intensity.

You could also find out:

• how often the grass is mowed;• how many people walk over it each day.

K6 Comparing the daisy

populations in two habitats

CHAPTER

WORKSHEET6

11


1 Here are descriptions of five different plants. Classify each plant into one ofthese groups:

moss fern conifer flowering plant

Plant A is about 15 mm tall. It has thin, dark green stems with really thin,almost transparent leaves. There are no veins in its leaves. There do not seemto be any flowers, but it does have little brown knobs on the ends of thinstalks. Plant A is a

..............................................................................................................................

Plant B is a large tree. It has large, broad green leaves with a network of veinsin them. In spring, it has greenish flowers that dangle down from its twigs.Plant B is a

..............................................................................................................................

Plant C is also a large tree. It is very tall and has a straight trunk. It has darkgreen needles. At some times of year, there are brown cones on its branches.Plant C is a

..............................................................................................................................

Plant D is about 75 cm tall. It has dark green leaves that start off curled up ina spiral and unfurl as they grow. Some of the leaves have brown specks allover the back of them. There are veins in the leaves. There do not seem to beany flowers. Plant D is a

..............................................................................................................................

Plant E has strap-shaped leaves about 30 cm long, but with its tall flowerspikes it is nearly 60 cm tall. The leaves have parallel veins in them. Theflowers are green and dangle downwards. Plant E is a

..............................................................................................................................

(5)2 Complete these sentences, using some of these words:

invertebrate population consumer food chaincommunity adapted producer pyramid

All the living organisms that live in a habitat are known as the ....................... .

Each organism is ........................ to live in that particular habitat. All the

organisms belonging to one species in the habitat make up a ....................... .

(3)

End of Unit test


CHAPTER

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3 Jane works as a conservation officer in theChilterns Area of Natural Beauty. She is worriedthat the populations of frog orchids on twohillsides may be getting smaller.

Jane uses quadrats to find out how many frogorchids are growing on each hillside.

a Which of these would be the best size of quadrat for Jane to use? Draw a circle around the one you would choose.1 cm square0.5 m square2.0 m square20 m square

(1)b Describe how Jane should choose where to place her quadrats on the

two hillsides.

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(2)Here are some of Jane's results.

c Calculate the total number of frog orchids that Jane found on each hillside, and write your answers in the table.

(2)d Jane’s results showed that on one hillside the frog orchids were quite

evenly spaced, while on the other they were in patches. Which was which?

(1)e To answer her question about whether or not the frog orchid populations

are decreasing, Jane needs to carry out her sampling again next year. Explain how and when she should do this, in order to obtain reliable results.

..............................................................................................................................

..............................................................................................................................

(2)



Quadrat 1 2 3 4 5 6 7 8 9 10 Total

Number of frogorchids on hillside A 0 0 8 3 0 12 1 0 2 0

Number of frogorchids on hillside B 2 4 1 0 2 3 0 2 1 2


4 A woodland contains tall oak trees, with smaller hazel bushes growing inbetween them. Small flowering plants grow on the woodland floor. Dormicelive in the hazel bushes and eat hazel nuts.

A local Wildlife Trust looks after the wood. Each winter, they coppice thehazel bushes in one part of the wood. This involves cutting them down tojust above the ground.

a The next year, more flowering plants grow in this part of the wood than before. Suggest why this happens.

..............................................................................................................................

..............................................................................................................................

(1)b Suggest why the people from the Wildlife Trust are careful not to

coppice all of the wood at once.

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(1)

5 Here is a food chain from a lake.

pondweed � tadpoles � great diving beetles � perch � heron

a Sketch a pyramid of numbers for this food chain.

(2)b On your pyramid, label each level with one of these names:

producer herbivore carnivore

(2)c Which organisms in the food chain are consumers?

..............................................................................................................................

(1)



d Write out a food chain that this pyramid of numbers could represent.

..............................................................................................................................

..............................................................................................................................

(2)

Total marks: 25

Extension question6 Kyle likes fishing in a shallow stream. He has noticed that there seem to be a

lot of freshwater shrimps where the stream flows around a bend, but fewershrimps where the stream flows along a straight stretch. There is a large treeovershadowing the stream on the bend. The water flows more slowlyaround the bend than in the straight part, and the bottom is muddy on thebend and stony in the straight part.

Kyle thinks that perhaps the shrimps prefer to live where there is mud ratherthan where there are stones. He decides to investigate this.

a Kyle decides to do his investigation in a laboratory rather than in the stream. Explain why this is a good idea.

..............................................................................................................................

..............................................................................................................................

(2)

(continued on next page)



b Describe how you would carry out this investigation. Write your descriptionin enough detail so that someone else could carry it out without having toask you anything.

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(6)c Suggest two other factors, other than the muddy bottom, that could

be the reason why there are more shrimps at the bend than in the straight part of the stream.

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..............................................................................................................................

(2)




Text answers1 a reptile – scaly skin. 2 a arthropod

b mammal – hair b cnidarianc bird – feathers/beak c molluscd fish – scales and fins d annelide amphibian – smooth skin

3 a Six legs, wingsb Many pairs of jointed legs, body divided into a head and many segmentsc Eight legsd More than 8 jointed legs, 2 pairs of antennae, body divided into ‘head-thorax’ and abdomen

4 Polar bear – very cold places/the Arctic; thick coat to keep warm, large pawsto support on ice or snow, large body to keep heat in, white hair forcamouflageStickleback – freshwater stream; gills for breathing under water, fins and tailfor swimming, streamlined shape for swimming

5 Pupils could suggest almost any freshwater aquatic organisms – but watchout for marine ones!

6 You want a quadrat that can contain several individuals, but not so largethat it becomes difficult to count them.a 0.5 m b 0.5 m c 20 m d 2 cm

7 a You could collect a number of leaves from one area, and use this number to make an estimate of the number of leaves on the tree. Count all the greenfly on the leaves you have collected or count a sample of them. Then multiply up to obtain an estimate of the number on the whole tree.

b You could use a sweep net to catch a sample of water boatmen. The net could be swept through the water so that a known volume was sampled. Then estimate the volume of the whole pond and multiply up.

Both of these methods are obviously highly unreliable – especially theboatmen, which can swim fast and evade capture.

8 a Oak tree, moss b Everything elsec Answers will vary d Answers will vary

9 a Diagram C b Diagram A c Diagram B

Literacy activityNo answers

End of chapter questions1 a community b population c invertebrate d pyramid of numbers

e quadrat2

Ecological relationshipsCHAPTER

11

ANSWERS

a b

c


Moss Fern Conifer Flowering plant

Does it have leaves? yes yes yes yes

If so, are the leavesneedles? no no yes no

Do the leaves have veins but veins butlots of veins? no not lots not lots yes

Which has the thickestand which has the may be may bethinnest leaves? thinnest thickest thickest

What are the differences spores may may be might bebetween the top and the be visible darker and waxier or havebottom of the leaves? on underside shinier on top hair on one side

Does it have flowers? no no no yes

Does it have cones? no no yes no

Does it have strong roots? no yes yes yes

What other differences depends on depends on depends on depends oncan you see between specimen specimen specimen specimenthese plants? provided provided provided provided

3 a They both go up and down (oscillate) b Warmer temperatures, more foodc More greenfly to eat d More are eaten by ladybirdse i Fewer greenfly in spring, so fewer ladybirds. There are then several

possibilities – accept any well-argued suggestions. For example, with fewladybirds the greenfly population might shoot upwards a little later. Or both may stay low all year.

ii Fewer greenfly, so fewer ladybirds.

Worksheet answersK1 Classifying animalsThere are several different possible features that pupils may choose for eachgroup. The list below includes some of the most likely answers, but be preparedto accept other valid suggestions.

Vertebrates – have a backbone, have an internal skeletonInvertebrates – do not have a backboneMammals – have hair, suckle their young, young develop in uterusBirds – have feathers, have a beak, forelimbs modified as wings, lay

eggs with hard shellsReptiles – have scaly skin, lay eggs that may have soft shellsFish – have scales, have gillsAmphibians – have a smooth skin, adults often live on land and tadpoles in waterMolluscs – have a soft body that often has a shell, no legsArthropods – have jointed legs, exoskeleton, body divided into segmentsAnnelids – soft body divided into segmentsCnidarians – soft circular body with tentaclesCrustaceans – more than four pairs of legsInsects – three pairs of legs, two pairs of wings, body divided into head,

thorax and abdomenK2 Four groups of plantsThese are the most likely answers. There will, however, be exceptions – forexample, there are conifers that do not have needles – so you should checkagainst the actual specimens that have been provided.

Chapter 11 Answers

455

K3 Classifying plantsa coniferb mossc flowering plantd conifere fernf flowering plant

End of Unit test answers1 A moss; B flowering plant; C conifer; D fern; E flowering plant (5)2 Community, adapted, population (3)3 a 0.5 m square (1)

b Use random numbers; as coordinates (2)c 26, 17 (2)d A patchy and B evenly spaced (1)e In the same area; at the same time of year; use same method to place the

quadrats (max. 2)4 a More light let in (1)

b To leave habitat for dormice (1)5 a Pyramid made up of centrally stacked rectangles; largest box at base

getting smaller towards the top (2)b Producer against pond weed, herbivore against tadpoles, carnivore

against great diving beetles, perch and heronall three correct for 2 marks, two correct for 1 mark (2)

c All except the pond weed (1)d One mark for suitable organisms; one mark for arrows going the right

way between them (2)Total marks for Extension: 25

Extension answers6 a Impossible to control variables in the stream or you can control variables

in the laboratory; so you cannot investigate just mud and stones in the stream/other things may be causing any differences you find. (2)

b (Pupils are likely to build on the work that they did investigating woodlouse behaviour in Year 7, so may suggest using choice chambers)Award marks for any of the following:at least 10 shrimps used;method of giving them a choice between mud and stones;suggest that at least one other variable is controlled;suitable method suggested for controlling this variable;mention of controlling at least three important variables;what is counted clearly described;when it is counted clearly described;how the results will be recorded clearly described (max. 6)

c Any two of speed of water flow, light intensity, oxygen concentration in the water, food supply, water temperature (2)




Chapter 11 Answers

Pupils should be familiar with the following ideas:• That magnets attract magnetic materials• That magnets can attract and repel other magnets• That magnets have a range of uses in everyday life• The construction of simple circuits and the use of power supplies

12 Magnets and electromagnets

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Starting points


AttractCompassCoreDomainDomain theory

ElectromagnetMagnetMagneticMagnetic fieldMagnetic shield

MagnetisedNon-magneticNorth polePermanentPlotting compass

RelayRepelSolenoidSouth poleUnmagnetised

In this topic pupils should learn:• to identify iron, steel, nickel and cobalt as magnetic materials• to distinguish between magnetic materials and non-magnetic materials• to make a permanent magnet and to explain how the magnet works using

domain theory• to describe how magnetic shielding occurs• to make an electromagnet and use it to sort magnetic materials from non-

magnetic materials• to describe some uses of permanent magnets and electromagnets• to describe the shape and direction of the magnetic field around bar magnets,

the Earth and solenoids• to describe how the Earth’s magnetic field can be used for navigation

Learning checklist

Links

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Unit Title3E Magnets and Springs


Unit Title7J Electrical Circuits


CH A P T E R

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Most pupils

Scientific enquiry• Make predictions about the behaviour of magnets and magnetic materials and

draw conclusions from patterns in evidence• Identify factors affecting the strength of electromagnets• Make sufficient observations in an investigation of electromagnets to draw

conclusionsPhysical processes• Distinguish between magnetic and non-magnetic materials• Describe magnetic shielding• Make a permanent magnet and an electromagnet• Describe how the Earth’s magnetic field can be used for navigation• Describe the shape and direction of a magnetic field• Give examples of the use of magnets and electromagnets

Pupils who have not made so much progressScientific enquiry• Suggest how to carry out a test to distinguish between magnets and magnetic

materials• Make changes to vary the strength of an electromagnetPhysical processes• Identify steel and iron as magnetic materials• Make a magnet and electromagnet• Describe the use of an electromagnet in sorting materials

Pupils who have progressed furtherScientific enquiry• Use a model of the magnetic field to explain phenomenaPhysical processes• Explain how magnetic materials can be magnetised using a simple

particle/domain model• Identify similarities in the magnetic fields of a bar magnet, the Earth and a

straight coil• Describe the shape of the field around a straight current-carrying conductor

Learning outcomes



LiteracyThere is a literacy activity on Benjamin Franklin in the Pupil Book.

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The Pupil Book introduces this chapter by looking at the history of the name‘magnet’ and by reminding pupils of the work on magnets that they have studiedat Key Stage 2. As a class activity pupils can list some names and uses of magneticmaterials. Pupils should remember that magnets attract magnetic metals such asiron, steel, nickel and cobalt and other magnetic materials such as iron oxide.

Attraction and repulsionPupils should than be given Worksheet L1, A magnetic problem, and a set ofthree metal bars, comprising two magnets and one steel bar. All three bars shouldlook similar. Pupils should be asked to identify which of the three bars are themagnets. Pupils should try out their ideas and be helped to appreciate that, whilemagnets can attract both other magnets and unmagnetised steel, magnets canonly repel other magnets, so that repulsion is the true test of whether a materialis really a magnet. Pupils can also be introduced to the idea of poles and asked tosolve the puzzle in question 3 on the worksheet.

The hovering paper clipIn this section pupils will investigate magnetic shielding. Pupils can be shown howa magnet still attracts iron filings even through a piece of paper, and asked torecall any other situation where they have encountered a magnet acting throughanother object (games, fridge magnets). Pupils can be shown the ‘hovering paperclip’ illustrated on page 162 of the Pupil Book, and can be asked to set it upthemselves. Pupils should also have access to a range of objects that they canplace between the magnet and the paper clip. Pupils should realise that althoughthe magnet will continue to work through non-magnetic materials such as plasticand paper, it does not work through magnetic materials. If a magnetic material isplaced between the magnet and the paper clip, magnetic shielding occurs andthe paper clip will fall.

The domain theoryThis section is a quick introduction to the domain theory, aimed at the more ablepupil.

Making magnetsIn this section pupils should magnetise an object made from a material such assteel. Pupils can be shown the ‘stroking method’ for making a magnet, which isillustrated in Worksheet L2, Making magnets. Pupils should be asked to make thestrongest possible magnet. Pupils should be encouraged to decide on how thestrength of the magnet can be tested (number of paper clips is normally thefavourite).

Destroying magnetismPupils are introduced to some of the ways in which magnetism can be destroyed.

The Earth’s magnetic fieldIn this section pupils learn about the work of William Gilbert who discovered thatthe Earth has a magnetic field.

Making a compassPupils can then investigate how a simple compass can be made by suspending amagnet from a length of cotton. Pupils should appreciate that the compass worksbecause the Earth has its own magnetic field.


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Magnetic fieldsPupils can then be asked to consider the nature of magnetic fields. The magneticfield around a magnet can be demonstrated using an OHP and iron filings. Pupilsshould appreciate that magnetic fields are strongest at the poles of the magnet.They should also be aware that if two magnets are placed close to each other theirfields interact and change shape. If available, a magnaprobe can also be used todemonstrate the magnetic field. Pupils should then be shown how to use a plottingcompass to investigate the direction of the magnetic field around a magnet. Pupilsshould produce a diagram showing the direction of the magnetic field by followingWorksheet L3, Plotting the direction of a magnetic field.

ElectromagnetsPupils should be shown some of the uses of electromagnets described on page 166of the Pupil Book, and also the maglev (magnetic levitation) train on page 160.Pupils should then be given the opportunity to make an electromagnet and toinvestigate how the number of coils affects the strength of the electromagnet usingWorksheet L4, Investigating electromagnets.

Pupils will probably already be aware of how to use power packs from the workcovered in Year 7 Chapter 10, Electrical circuits. However, make sure that youexplain how the power packs they will be using work. Point out the d.c. terminals(which the pupils will be using) and explain how the voltage can be altered. It isalso worth pointing out that you expect the power packs to be put away in a neatand tidy way, with the leads safely wrapped around the packs, etc. Although youwill probably not be able to stand by them at the end of the lesson, you canpublicly appoint someone to monitor their return.

This is a good opportunity to teach pupils how to evaluate an investigation, andsome questions to develop this skill are given on the worksheet.

Pupils can be reminded of how they made and tested an electromagnet. Theyshould remember that the electromagnet attracted steel paper clips and thatincreasing the number of coils increased the strength of the electromagnet. Themagnetic field around an electromagnet can be demonstrated using an OHP andiron filings. Pupils should recognise the pattern as being similar to the magneticfield they observed earlier with a permanent magnet. Pupils can also be shownthat the solenoid still has a magnetic field around it even when the soft iron core isremoved (although the strength of the field is much reduced). For more able pupilsthis is described and illustrated on page 166 of the Pupil Book. The effect of thesize of the current on the strength of the electromagnet is also discussed on page167 of the Pupil Book.

RelaysPupils should then learn about how electromagnets are used from the example ofthe relay on page 167 of the Pupil Book. Pupils can then be asked to investigateanother device that uses an electromagnet, such as a buzzer or bell using secondarysources (CD-ROMs, books, internet) and to explain, using diagrams, how it works.



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Some pupils may believe that all metals are magnetic and this commonmisconception can be discussed and explored through demonstration.

Destroying magnetismWhen discussing this, emphasise that pupils must be very careful not to drop themagnets.

The Earth’s magnetic fieldWhen covering this section be aware that a common misconception at this level isto confuse gravity and magnetism.

Making a compassBe aware that attaching your compass to a magnetic material may giveanomalous results.

Magnetic fieldsTo reduce the mess, cover the magnet in clingfilm at the start of the experimentand sprinkle the filings from a pepper pot on to a clean OHT.

The method illustrated on Worksheet L3, Plotting the direction of a magnetic field,is quite complex: it may prove useful to go over it quickly as a class activity.




Sc1

Scientific Enquiry

1a, 1c, 2e, 2h, 2k, 2n, 2o, 2p

Sc2


Sc3


Sc4

Physical Processes

1d, 1e, 1f


What I have learnt

Magnets and electromagnets


North pole

Compass

Attract

Domain

Electromagnet

Magnetised

Plotting compass

Core

Relay

Magnet

South pole

Magnetic shield

Non-magnetic

Unmagnetised

Magnetic field

Repel

Permanent

SolenoidDomain theory

Magnetic


• I know that iron, steel, nickel andcobalt are magnetic materials

• I can distinguish between magneticmaterials and non-magneticmaterials

• I can make a permanent magnet

• I can explain how the magnetworks using domain theory

• I can describe how magneticshielding occurs

• I can make an electromagnet anduse it to sort magnetic materialsfrom non-magnetic materials

• I know some uses of permanentmagnets and electromagnets

• I can describe the shape anddirection of the magnetic fieldaround bar magnets, the Earth andsolenoids

• I know how the Earth’s magneticfield can be used for navigation

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on this topic

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Lesson Focus Pupil Book 2 p. 160–161What can magnets do?

Expectations

Most Pupils Can identify a wide range of magnetic materials and work outwhether a material is a magnet or not.

Less Able Pupils Can identify iron and steel as magnetic materials and give a use ofmagnets.

More Able Pupils All of the above, plus can explain why repulsion is the only truetest of whether a material is a magnet or not.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Reading of section on legends about magnets.Numeracy:ICT:


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Worksheet L1 A magnetic problemPer group:Three similar metal bars, two of whichare magnets and one is steel but not amagnet

Optional:Useful magnetsFridge magnet/magnetic game

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20 In and register. More able pupils will take a more active part Pupils recall that iron, steel, nickel, cobalt and iron oxide are Starter. Introduce the topic using the Pupil Book. Use Q & A to remind pupils in discussion. magnetic materials. Pupils can give some uses of magnets.of the magnetic materials and their uses that they have studied at Key Stage 2. Some less able pupils may benefit from seeing Instruct pupils to answer questions 1 and 2 on page 161 of the Pupil Book. some examples of magnets.Remind pupils that the ends of the magnet are called the poles.

20 Development. Distribute Worksheet L1 A magnetic problem and introduce Less able pupils may need more help to develop Pupils can plan and try out their own ideas.the activity. Explain that each group has to find out which of the bars are and try out their ideas.magnets.

10 Plenary. Use class discussion to review the pupils’ investigations. Help pupils Pupils appreciate that repulsion is the only true test of to conclude that while magnets will attract both other magnets and steel, only whether a material is a magnet.magnets will repel other magnets. This is discussed at the foot of page 161 of the Pupil Book.

Homework: Questions 1 to 3 from Worksheet L1.


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Lesson Focus Pupil Book 2 pp. 162–163Magnetic shielding and making magnets

Expectations

Most Pupils Can explain why the paper clip hovers and can predict whichmaterials will make it fall.

Less Able Pupils Know how a magnet can be made and how magnetism can bedestroyed.

More Able Pupils All of the above, plus can explain magnetic shielding withconfidence.



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Demo: Magnet and iron filingsOHT/paperMagnetIron filings

The hovering paper clipPer group:Thin cottonBlu-Tack/sticky tapeMagnetPaper clipClamp standAccess to a range of materials to placebetween paper clip and magnet,including a small sheet of iron or steel

Worksheet L2 Making magnetsPer group:Steel nailMagnetPaper clips

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10 In and register. Pupils appreciate that a magnet can attract another material Starter. Introduce this section with Magnet and iron filings demo. Emphasise even though they may not be in direct contact with each that the magnet attracts the iron filings even through the paper. Use Q & A to other.recall other situations in which pupils have encountered a magnet acting through Pupils can give some uses of magnets.another object or material.

15 Development. Show pupils The hovering paper clip. Ask them to name the Less able pupils may need more help to find the Pupils can explain magnetic shielding.material through which the magnet is working (air). Instruct pupils to set up rule. Consider teaming up more able and less able their own hovering paper clip and then to find if the magnet will work through pupils.all or just some materials. Ask the pupils to try and find a rule and to test the rule to see if it is always right.Use page 162 of the Pupil Book to explain magnetic shielding.

15 Distribute Worksheet L2 Making magnets and show pupils the stroking Domain theory can be discussed with more able Pupils know how to use the stroking method to make a method for making magnets. Instruct pupils to make the strongest magnet pupils. magnet.possible. Encourage pupils to think of ways that they could test the strength of their magnet. Discuss the advantages and disadvantages of the different methods of testing magnetic strength.

10 Plenary. Use a quiz format to summarise work on magnetic shielding and Pupils can consolidate their ideas.making and destroying magnetism. Emphasise not dropping the magnets.

Homework: Questions 3 and 4 on page 163 of the Pupil Book.


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Lesson Focus Pupil Book 2 pp. 164–165Magnetic fields

Expectations

Most Pupils Know how to find the shape and direction of the magnetic fieldaround a magnet using iron filings/plotting compass.

Less Able Pupils Know that the Earth has a magnetic field. Can find the shape ofthe magnetic field around a magnet.

More Able Pupils All of the above, plus know how to find the shape and direction ofthe magnetic field around a magnet using iron filings/plottingcompass. Can explain how a compass works.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Section on page 164 of the Pupil Book on William Gilbert.Numeracy:ICT: Optional magnaprobe to demonstrate magnetic field around a magnet.


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Demo: Making a compass MagnetThin cottonSomething to suspend magnet from, e.g.wooden stool placed upside down

Demo: Magnetic field around amagnetTwo magnets (in clingfilm)Iron filings (in pepper pot for sprinkling)Optional: OHP, magnaprobe

Worksheet L3 Plotting the direction ofa magnetic fieldPer group:Two magnetsPlotting compassRuler

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10 In and register. Pupils appreciate that a compass works because the Earth has Starter. Use Q & A to reinforce the ways that magnets can be created and its own magnetic field.destroyed. Introduce the Earth’s magnetic field section from the Pupil Book. Show pupils the Making a compass demo. Explain how it works, then instruct pupils to answer question 5 on page 164 of the Pupil Book.

15 Development. Show pupils the Magnetic field around a magnet demo. Less able pupils may benefit from doing this Pupils know that the magnetic field is strongest at the poles. Emphasise that the iron filings show that the magnetic field is strongest around activity as a practical, but it can get very messy. Be familiar with the shape of the magnetic field around a the poles of the magnet. Show how the magnetic fields of two magnets interact magnet.(North–North and North–South). If one is available, a magnaprobe could also be used.

15 Explain that the iron filings were useful but they did not show the direction of Less able pupils will need quite a bit of assistance Pupils can find the direction of the magnetic field around a the magnetic field, only its shape. To find the direction a plotting compass is to complete this activity. Consider running through magnet.needed. Distribute Worksheet L3 Plotting the direction of a magnetic field. the instructions on the board once they have read Instruct pupils to find the direction of the magnetic field around the magnet, and the sheet.around two magnets placed close together (North–North and North–South).

10 Plenary. Use class discussion to review and explain the pupils’ results. Pupils can consolidate their ideas.



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Lesson Focus Pupil Book 2 pp. 165–167Electromagnets

Expectations

Most Pupils Can make an electromagnet and investigate how the number ofturns affects the strength of this electromagnet. Begin to evaluatetheir work.

Less Able Pupils Know that electromagnets can be turned on and off. Can make anelectromagnet.

More Able Pupils All of the above, plus can evaluate their work with confidence.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy: Counting the number of turns and the number of paper clips picked up. Analysing results to find correlations.ICT:

Cross-curricular developmentMaths: positive correlations.

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Optional demo: ElectromagnetsElectric bell/buzzer

Worksheet L4 InvestigatingelectromagnetsPer group:Long piece of plastic-coated wireSoft iron nailPaper clips (to test strength ofelectromagnet)Power pack

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10 In and register. Pupils know electromagnets can be turned on and off.Starter. Use the photographs on page 166 of the Pupil Book and do the optional electromagnets demo to introduce electromagnets. Explain that electromagnets are particularly useful because they can be turned on and off.

25 Development. Distribute Worksheet L4 Investigating electromagnets. Show Less able pupils may need more help to set up Pupils have experience of making an electromagnet. Pupils can the pupils how to set up an electromagnet, then ask them to find out how and carry out the experiment. investigate the effect of changing the number of coils on the altering the number of turns affects the strength of the electromagnet. strength of the electromagnet.Instruct pupils to answer questions 1 to 4 on the worksheet.

15 Plenary. Discuss the pupils’ results, then use class discussion to cover all the More able pupils will take a more active part in Pupils begin to evaluate their own work.aspects of question 5 on the worksheet. class discussion.

Homework: Question 5 from Worksheet L4.


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Lesson Focus Pupil Book 2 pp. 166–167Using electromagnets

Expectations

Most Pupils Can explain how electromagnets are used in familiar situations.

Less Able Pupils Can recall some uses of electromagnets.

More Able Pupils Can explain how electromagnets are used in unfamiliar situations.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Numeracy:ICT: Optional use of internet or CD-ROMs to investigate uses of electromagnets.


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Demo: Magnetic field around anelectromagnetLong piece of plastic-coated wireCardboardIron nailPower packIron filings

Electromagnet postersLarge pieces of paperColoured pencilsAccess to secondary sources (CD-ROMs,books, internet)

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10 In and register. More able pupils can use the Pupil Book to Pupils realise that the magnetic field around an electromagnet Starter. Remind pupils of how they made and tested an electromagnet. They consider how the domain theory can be used to is similar to the magnetic field around a permanent magnet.should be able to recall that the more turns, the stronger the electromagnet explain how the presence of a soft iron corebecame. Show pupils Magnetic field around an electromagnet demo. Ask increases the strength of the electromagnet and pupils what the pattern reminds them of (shape of magnetic field around a to explain the effect of the size of the current on permanent magnet). Remove the iron nail and show that there is still a (weaker) electromagnet strength.magnetic field. Use the Pupil Book to consolidate these ideas.

30 Development. Instruct pupils to read the section on relays in the Pupil Book. Consider teaming up more able with less able Pupils understand how electromagnets work and can practise Explain how each part of the relay works. Divide the class into small groups pupils. applying this knowledge to unfamiliar situations.(3 or 4). Instruct pupils to use secondary sources (CD-ROMS, books, internet) to produce a poster in answer to question 7 on page 167 of the Pupil Book.

10 Plenary. Discuss and display the posters produced by each group. Pupils know that electromagnets can be used in a variety of different situations.

Homework: Complete posters.


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Lesson Focus Pupil Book 2 Chapter 12Revision and consolidation of Chapter 12End of Unit test

Expectations

Most Pupils Have an understanding of the uses of magnets and electromagnets.

Less Able Pupils Have a basic understanding of the topic.

More Able Pupils All the above, plus will be fluent in all aspects of the topic using afull range of subject specific vocabulary.

Development of Key Skills (Literacy, Numeracy, ICT)Literacy: Identify and explain the key words.Numeracy:ICT:


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20 In and register. Pupils have a record of the main ideas of the topic.Remind pupils of the main ideas of the topic. Direct pupils to answer questions 1 and 2 on page 170 of the Pupil Book.

30 Sit pupils in appropriate test conditions. Pupils complete the End of Unit test. More able pupils will answer more questions Pupils consolidate knowledge gained by completing the End Those who have completed the test well within the 30 mins can tackle the correctly and will attempt the extension questions. of Unit test.extension question after they have checked through all their answers.

Homework: Questions 3 and 4, and 5 if time, on pages 170–171 of the Pupil Book.


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474

UN I T

You have been given three metal bars. They all appear similar, but two ofthe bars are magnets while the third bar is made of steel but is not amagnet.

Two of these bars are magnets

You are to find out which of these three metal bars are magnets. You mayuse only the three bars and no other equipment.

Explain how you decided which of these bars are the magnets.

L1 A magnetic problemCHAPTER

WORKSHEET1

12


1 What are the ends of a magnet called?

2 Which of these pairs of magnetsa attract each other?b repel each other?

3 A magnet is on a table, and is attracting two nails.

Complete the diagram to show the north pole and the southpole of each of the nails.

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NN

N Na

b

c

d

N N

N N

S S

SS

SS

SS

N S

nail

magnet

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UN I T

L2 Making magnetsCHAPTER

WORKSHEET2

12


A magnetic object such as an steel nail can be made into a magnet. Thesimplest way to do this is to take an steel nail and stroke it with a magnet.The nail should be stroked lots of times in the same direction.

In this investigation you are asked to make the strongest possible magnet.

1 Explain how you have made your magnet as strong aspossible.

2 How did you test the strength of the magnet you made?3 How strong was your magnet?

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steel nail

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➤continued

1 Place your magnet in the centre of your piece of paper.2 Carefully draw around the magnet (if you accidentally move the magnet

later you can put it back in exactly the same place).

3 Place your plotting compass at one corner of your magnet.4 When the needle stops moving make two marks, one at the head of the

compass arrow and one at the tail of the compass arrow.

5 Remove the compass and join the points using a ruler. Mark the directionof the magnetic field with an arrow.

UN I T

L3 Plotting the direction of a

magnetic field (page 1)

CHAPTER

WORKSHEET3

12

NS

477

UN I T

L3 Plotting the direction of a

magnetic field (page 2)

CHAPTER

WORKSHEET3

12


6 Make sure the magnet is still in position. Place the compass down so the tailof the compass arrow is now exactly where the head of the compass arrowwas previously.

7 Repeat steps 4 to 6 until you run out of paper.8 Repeat for the remaining corners of the magnet.

Making an electromagnet

1 Take a long length of wire and an iron nail. Carefully wrap the wirearound the nail 10 times. This will be your electromagnet.

2 Connect both ends of the wire to the d.c. terminals of your power pack.

3 Set the voltage of the power pack to approximately 2 V. Then turn on thepower pack. Hold one end of the nail close to a paper clip. If the paper clipis attracted to the nail, your electromagnet is working. If it is not, ask yourteacher to check the circuit. Be careful not to use too high a voltage, asthe current flowing through the coil may cause it to become hot.

4 See how many paper clips you can pick up with your electromagnet. Putyour result in the table on the next page.

5 Turn off the power pack. Add 10 more turns to your coil.

6 Turn on your power pack. See how many paper clips you can now pick up.Enter this result in your table.

478

UN I T

L4 Investigating electromagnets

(page 1)

CHAPTER

WORKSHEET4

12


soft iron nail turns in coil of wire

➤continued

479

7 Repeat steps 5 and 6 until you have 50 turns of wire on your nail.Complete the table.

L4 Investigating electromagnets

(page 2)

CHAPTER

WORKSHEET4

12


1 How does the number of turns affect the strength of anelectromagnet?

2 Think carefully about your investigation. Did you take a largeenough range of results?

3 Did you repeat any of your results to increase the accuracy ofyour findings?

4 Were there any readings that appear not to fit the trend ofyour results? These are sometimes called anomalous results.

5 If you could do it again, how could you improve yourinvestigation?

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Number of turns in coil of Number of paper clipselectromagnet picked up


1 Which of these materials would be attracted to a magnet?

iron iron sulfide copper cobalt steel magnesium

..............................................................................................................................

..............................................................................................................................

..............................................................................................................................

(3)2 Which of these pairs of magnets would

a attract each other?b repel each other?

a Attract = ................................... b Repel = ...................................

(1)

3 a How could you show the shape of the magnetic field around a bar magnet?

..............................................................................................................................

(1)b How can the direction of a magnetic field be shown?

..............................................................................................................................

(1)c Where is the magnetic field around a magnet strongest?

..............................................................................................................................

(1)

End of Unit test


CHAPTER

12

NS NS

NSA

B

SN

481

4 This steel paper clip is attracted to the magnet. Which of the followingmaterials could be used to shield the paper clip from the magnet’s magneticfield?

paper plastic cardboard steel cotton rubber

..............................................................................................................................

(1)

5 a How could you make a steel nail into a magnet?

..............................................................................................................................

(1)b How could you make your magnet stronger?

..............................................................................................................................

(1)c How can you destroy the nail’s magnetism?

..............................................................................................................................

(1)

6 An electromagnet can be made by passing an electric current through a coilof wire. Give two ways to increase the strength of an electromagnet.

..............................................................................................................................

..............................................................................................................................

(2)



sticky tape

retort stand

magnet

paper clip

cotton thread


7 Electromagnets can be used in buzzers. Give two other uses ofelectromagnets.

..............................................................................................................................

..............................................................................................................................

(2)8 An electromagnet can be used to operate a hacksaw blade.

a What happens to the coil and the iron core when electricity passesthrough the coil of wire?

..............................................................................................................................

(1)b What happens to the hacksaw blade?

..............................................................................................................................

(1)c Is the circuit now complete?

..............................................................................................................................

(1)d What happens to the electromagnet?

..............................................................................................................................

(1)e What happens to the hacksaw blade?

..............................................................................................................................

(1)

Total marks: 20


springy steel hacksaw blade

power supply

wiresoft iron core

coil

contact

switch


Extension questions

9 a Explain how you could make a compass.

..........................................................................................................................

(1)b Why does the compass work?

..........................................................................................................................

(1)10 Relays are found in cars. Explain what a relay does. You may include a

diagram in your answer if you wish.

..........................................................................................................................

..........................................................................................................................

..........................................................................................................................

..........................................................................................................................

..........................................................................................................................

..........................................................................................................................

(3)




Text answers1 a No

b Iron, steel, nickel and cobaltc Two from many, e.g. copper, tin, chrome, magnesium, zinc and aluminium

2 Two from fridge magnets, games, scrap yard metals being sorted, removingmetal objects from person’s eye, magnetised screwdriver and screw, etc.

3 a The north pole of the existing magnet attracts the south poles of the tiny domains in the iron bar. Each time the iron bar is stroked with the magnet more domains line up in the same direction, so the iron becomes a stronger and stronger magnet.

b Because otherwise the magnets in the domains will not line up in the same direction.

4 It can knock the domains out of line, and so destroy the magnetism.5 a Suspend the magnet so it is free to rotate.

b The magnet in the compass lines up with the Earth’s magnetic field.6

7 Answers will vary but should include details of how electromagnets can beturned on and off: when the current is switched on, a magnetic field iscreated around the coil, but when no current flows the magnetic fielddisappears. For example, for a bell, when the switch is turned on, the currentflows through the coil. This attracts the hammer of the bell, which strikesthe bell. However, this movement breaks the circuit, which turns off theelectromagnet, so the hammer returns to its original position.

8 Because a small (safe) current in one circuit can turn on and off a muchlarger (less safe) current in a second circuit.

Literacy activity answersa He founded the first public library, Philadelphia’s University, fire department

and police force.b He tied a metal key to the string of a kite and then flew the kite into a big

thunderstorm. Static electricity from the storm clouds travelled down thekite string to the metal key and then jumped to nearby objects causing aspark.

c It was very dangerous.

Magnets and electromagnetsC

HAPTER

12

ANSWERS

a b c

S N S N SN S N NS


d The strips of metal that make up the lightning conductor are a much betterconductor of electricity than the brick or stone used for the building. Iflightening strikes the building, the electricity travels down the lighteningconductor to the Earth without destroying the building.

e He became one of the founding fathers of the new country and helped towrite the Declaration of Independence, which promised freedom and libertyfor the people of America.

End of chapter answers1 a Magnetic field

b Polesc Electromagnetd Compass

2 a False b False c True d False e False f False g True3 a off

b pattern/shapec compass, direction

4 a It becomes magnetisedb It is attracted to the electromagnetc Nod No longer magnetisede Moves back to its original position

5 Answers will vary6 If a magnet is cut in half, two smaller magnets would be made because the

domains in each half of the original would still be lined up.

Worksheet answersL1 A magnetic problem1 Poles2 a a and d

b b and c3

Chapter 12 Answers

N

N

S

S

SN

N S N S

N S

S NS NS N

S NS N

S NS NS N

S NS NS N

S NS NS N

S NS NS N

S NS N

S

S NS NS N

S NS N

S NS NS N

S NS N

S NS NS N

S NS NS N

S NS NS N

S NS NS N

S NS N


L2 Making magnets1 By stroking it as many times as possible.2 Possible answer: by testing how many paper clips it picked up.3 Possible answer: my magnet was able to pick up five paper clips.

End of Unit test answers1 Iron (1), cobalt (1), steel (1)2 a B

b A (1)3 a (Sprinkle with) iron filings (1)

b (Plotting) compass (1)c Poles (1)

4 Steel (1)5 a Stroke it with a magnet (1)

b Stroke it more times (1)c Heat it/drop it/hit it (1)

6 Add an iron core/increase the number of turns/increase the current (max. 2)7 Relays/bells/scrap yard/any suitable suggestion (max. 2)8 a Becomes magnetised (1)

b It is attracted to the electromagnet/soft iron core/coil (1)c No (1)d No longer magnetic/turned off (1)e Returns to its original position/moves back/moves up (1)

Total marks: 20

Extension answers9 a Suspend a magnet so that it is free to rotate (1)

b It lines up with the Earth’s magnetic field (1)10 A relay is a kind of switch (1); a small current in one circuit (1)

is used to turn a second circuit on and off. (1)Total marks for Extension: 5


Chapter 12 Answers

Class

Name 1 2 3 4 5 6 7 8 9 10 11 12

End of Unit test mark record

Technician NotesEquipment and Resources

Atoms and elements

Lesson 1Materials

Demo: Objects made from differentmaterialsA selection of elements and compounds, e.g.silver ring, aluminium foil, graphite sticks, gasjar containing oxygen, wooden ruler, plasticruler, plant.

Worksheet A1 Elements wordsearchOne sheet per pupil (paper exercise).

Lesson 2Elements, their names and symbols/Compounds

Demo: Atom modelLego®, or other bricks that can be joinedtogether, in several different colours.

Worksheet A2 All about platinumOne sheet per pupil (for homework).

Chapter 1 Information sheet: Elements andsymbolsOne sheet per pupil (needed to completeactivities in Pupil Book).

Lesson 3/4Investigating elements

Worksheet A3 Properties of elementsGroup, then class, activity: about 16 sheets, cutup to complete for elements 1 to 89.Table about 75 cm x 100 cm on which to arrangeelements as in the periodic table.Access to data books, CD-ROMs and theinternet.

Worksheet A4 Properties of the elements inthe periodic tableOne sheet per pupil (paper exercise).

Mendeleev’s organisation of the elementsVideo clip: Channel 4 Learning ‘Big Questions:The Nature of Scientific Enquiry’, ISBN186215758-8, Track 4 Mendeleev’s dream.

Lesson 5New compounds from chemicalreactions

Demo: Chemical reactions forming newcompoundsHydrogen + oxygen � water: Hydrogen balloon.Sodium + chlorine � sodium chloride: Sand,sodium, crucible lid, gas jar containing chlorine.Carbon + oxygen � carbon dioxide: Toast toburnCopper + sulfur � copper sulfide: Copper, sulfur,borosilicate, boiling tube, mineral wool

Worksheet A5 Naming new compoundsOne sheet per pupil (for homework).

Lesson 6Making metal oxides

Practical activity: Making metal oxidesPer group: small pieces of magnesium, zinc andcopper to burn, Bunsen, tongs, safety mat.Per pupil: goggles.

Lesson 7Revision and consolidation ofChapter 1Per pupil: one set of End of Unit test sheets.

489

CHAPTER

1

When using any chemicals for any Lesson please refer to appropriateCLEAPSS, Hazcards and Recipe Cards.


Light

Lesson 1Light travels very quickly/Lighttravels in straight lines

Worksheet B1 Light travels in straight linesThree screens with small central hole, length ofthread (approx. 60 cm), luminous object, e.g.light bulb, length of Bunsen tubing (ca. 30 cm).

Lesson 2Transparency and shadows

Demo: Transparency, translucency, opacitySeveral sheets of clear glass and plastic, severalsheets of tracing paper and frosted glass, severalsheets of card. Optional: fabric lampshade.

Lesson 3Reflection of light

Worksheet B2 Reflection of lightPer group: Ray box and power supply, smallplane mirror, two small pieces of plasticine, A4paper, ruler, protractor.

Worksheet B3 Periscopes and kaleidoscopesPer group: Three small mirrors, cardboard orplastic tube (approx. 10 cm diameter) – pupilsshould have brought their own tubes, but spareswill be useful, scissors, sticky tape, small piecesof coloured plastic or paper, tracing paper.

Lesson 4The images created by a plane mirror

Worksheet B4 Finding the image in a planemirrorPer group: Five optical pins, small plane mirror,two small pieces of plasticine, A4 paper, ruler.Optional: softwood boards to put optical pins in.

Lesson 5Refraction of light

Demo: RefractionBeaker, water, pencil or ruler.

Worksheet B5 What happens to a ray oflight as it travels through a glass block?Per group: ray box and power supply,rectangular glass block, A4 paper, ruler.

Lesson 6Dispersion of white light by a prismto produce a spectrum ofcolours/Recombination of spectrumof colours to produce white light

Demo or class experimentGlass prisms, possible source of light needed,e.g. ray box.

Worksheet B6: Newton’s discPer group: One compass, one piece of stiff cardapprox. 15 cm square, pair of scissors, colouredfelt tips or pencils, 1 m of thread.

Lesson 7Mixing coloured lights to producenew colours/The colour triangle

Demo: Mixing coloured lightsThree light sources, one red, one blue and onegreen, a white screen.

Lesson 8Seeing coloured objects/The effectsof coloured filters

Demo: Coloured objects under colouredlights (optional)Red, green and blue light sources, room withvery good blackout.Per group: red, green and blue filters.

Lesson 9Quick revision of coloured lights,objects and filters/End of Unit test

Worksheet B7 Coloured lightsOne per pupil.Per pupil: one set of End of Unit test sheets

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491


Lesson 1The main groups of nutrients andwhy we need them/Analysing thenutrients present in a meal

Demo: Groups of nutrients and why weneed themFood label on page 38 of the Pupil Book, a fewsamples of 100 g of different foods, including abreakfast cereal.

The nutrients a meal containsComputers and software and/or Chapter 3Information sheet

Lesson 2Testing foods for protein and fat

Worksheet C1 Testing foods for protein andfatPer group: At least 5 different food samples,including meat, tinned fish, cheese, fresh fruitbread (pupils to bring their own, but extra willbe needed). Knife to cut food into small pieces.Clean dropper pipette (for milk or other liquidfoods), several clean test tubes in a rack. Biuretreagent and dropper pipette. Ethanol, cleanglass rod, goggles.

Worksheet C3 Which foods are goodsources of nutrients?Per pupil: One copy of Chart C3 Nutrients infoods for homework. Samples of food labels (inaddition to those brought by pupils).

Lesson 3Testing foods for starch and sugar

Worksheet C2 Testing foods for starch andsugarPer group: At least 5 different food samples,including milk, meat, bread, biscuit, fresh fruitincluding an apple, cheese, raisins, potato(pupils to bring their own but extra will beneeded). Knife to cut food into small pieces.Clean dropper pipette. Several clean test tubesin a rack. Water bath set at close to boilingpoint, with racks to hold test tubes. White tile.Iodine in KI solution, in small bottles withdroppers, Benedict’s solution.

Lesson 4What types of foods should bepresent in a healthy diet?

Food labelsSpares for those pupils without any.

Worksheet C3 Which foods are goodsources of nutrientsSpare for any pupil without one.

Chart C3 Nutrients in foodsTransparency of the chart and an OHP, orinteractive white board for data display.

Lesson 5Introduction to the alimentarycanal/Absorption in relation toparticle size

Worksheet C4 Absorbing carbohydratesPer group: A piece of Visking tubing roughly90–100 mm long (diameter unimportant), accessto starch suspension (conc. unimportant), accessto concentrated glucose solution (conc.unimportant), two clean dropper pipettes, smallbeaker into which the Visking tubing can beplaced, cotton to tie the tubing. Iodine in KIsolution, in small bottles with droppers,Benedict’s solution.

Lesson 6Digestion is necessary beforeabsorption/Enzymes as catalysts

Worksheet C5 Digesting starchPer group: Access to amylase solution, approx.0.1%, starch suspension, approx. 1%, iodine inKI solution with dropper, Benedict’s solutionwith dropper. Three clean boiling tubes in arack. At least one clean glass rod (three ifavailable). Three syringes or small measuringcylinders to measure 10 cm3. A beaker and accessto tap water. Means of labelling the tubes. Sightof clock. White tile. Access to a water bath ofvery hot water, with racks to hold boiling tubes.

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Food and digestion


492

Lesson 7Investigating the effect oftemperature on enzyme activity/Oneor two groups give presentation onan aspect of diet

Worksheet C6 How does temperature affectstarch digestion?Per group: Six clean boiling tubes in a rack.Means of labelling the tubes. A beaker andaccess to crushed ice. Access to a water bathcontaining very hot water, with racks to holdboiling tubes. Thermometer, white tile, twosyringes to measure 10 cm3, three clean glassrods. Access to 0.1% amylase solution (orappropriate concentration as previouslydetermined), 1% starch suspension, iodine in KIsolution.

Lesson 8

End of Unit test/Giving presentation on anaspect of dietPer pupil: one set of End of Unit test sheets.

Technician Notes



Lesson 1Elements, compounds and mixtures

Worksheet D1 Elements and compoundsOne per pupil plus access to scissors.

Pupil investigation: properties of a mixturePer group: A mixture of iron and sulfur, amagnet (wrapped in clingfilm), hydrochloricacid.

Demo: Making a new compoundIron and sulfur in a 7:4 ratio to heat carefully.

Worksheet D2 Particle modelsOne per pupil (for homework).

Lesson 2Can compounds react?

Worksheet D3 Observing reactionsPer group:Heating sucrose: boiling tube, Bunsen burner,sugar.An acid with a metal carbonate: hydrochloricacid, calcium carbonate, boiling tube,thermometer.Sodium carbonate solution with iron(II) chloride:test tube, sodium carbonate solution, iron(II)chloride solution.Dilute ammonia and copper sulfate solution: testtube, dilute ammonia, copper sulfate solution.

Lesson 3Mixtures

OptionalBottles of different mineral water, or labels fromthem.

Leaflet about airPlain paper, coloured pencils.

Lesson 4Using melting and boiling points

Information sheet: Temperature line

Worksheet D4 Boiling points of pure andsalty waterPer group: two beakers, salt, thermometer,Bunsen burner, distilled water.

Lesson 5Investigating a pure and an impureliquid

Worksheet D5 Investigating a pure and animpure liquidPer group: Salt, ice cubes, beakers/bowls, timer,thermometers, two boiling tubes. Solutionslabelled ‘a’ and ‘b’ (a is salty water and b isdistilled water). Plain paper, graph paper.


493

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494


Lesson 1Energy is obtained from food whenit reacts with oxygen inside cells

Demo: Worksheet E1 Energy from icingsugarA cardboard ‘tin’ with a lid, e.g. custard powdertin, with a hole in the side at candle flame level.A short length of rubber tubing which fitstightly in the hole. A short candle which sitsfirmly in the bottom of the tin. Means oflighting the candle. Icing sugar and a spatula tohelp to load it into the tubing at the tin end.

Lesson 2Detecting carbon dioxide producedby respiring organisms

Worksheet E2 Detecting respiration in livingorganisms: looking for carbon dioxidePer group: Four test tubes (or boiling tubes),each fitted with a gauze platform. Access towell-aerated hydrogencarbonate indicatorsolution. Clean dropper pipette. Test tube rackor beaker. Live maggots, live germinating peas,dead peas, small beads. Blunt forceps or othermeans of handling maggots.

Lesson 3Respiration produces a rise intemperature which can bedetected/Planning an investigationto compare the rate of respiration atdifferent temperatures

Worksheet E3 Detecting respiration in livingorganisms: looking for a temperature risePer group: two conical flasks, cotton wool tomake stoppers, insulating material for the flasks,two thermometers, boiled (sterilised) peas, livegerminating peas.

Worksheet E4 Investigating the rate ofrespirationOne sheet per pupil.Optional: proforma on which less able pupils canwrite their plan.

Lesson 4A planned investigation into howtemperature affects the rate ofrespiration

Worksheet E4 Investigating the rate ofrespirationSpare copies for any pupil without Worksheet.Per group: Four test tubes (or boiling tubes),each fitted with a gauze platform. Access towell-aerated hydrogencarbonate indicatorsolution. Clean dropper pipette. Test tube rackor beaker. Live, germinating peas, dead peas.Stopwatch or stopclock. Means of measuringvolumes of about 10 cm3, e.g. syringes. Access totop pan balance. Options for a widetemperature range: thermostatically controlledwater bath, beaker of crushed ice, beaker to putin fridge, beaker at room temperature.

Lesson 5The circulatory system

Circulatory system diagramsUnlabelled diagrams for pupils to label.

Historical ideas about human bloodcirculationPictures, OHTs, video clips, other material toillustrate the work of Hippocrates, Galen andIbn-al-Nafis.

Lesson 6Structure of the lungs and gasexchange

Demo: Lungs and their structureA set of lungs (e.g. pig, sheep) from butcher,large board or container for displaying lungs,fine rubber gloves, access to warm water andsoap for washing hands.

Worksheet E5 The discovery of the bloodcirculationOne sheet per pupil. Material to support andillustrate this, e.g. illustrations, video clips.

CHAPTER

5

Respiration


Lesson 7Comparing the composition ofinspired air and expired air/Emphysema

Worksheet E6 Comparing the carbondioxide content of inspired air and expiredairPer group: Two boiling tubes with bungs, glasstubing, rubber tubing (clean and disinfect beforeand after use), support for apparatus,hydrogencarbonate indicator solution, freshlymade and well aerated (lime water could beused instead), dropper pipette or small bottlesfor transferring indicator into the boiling tubes.Extension: candle, blue cobalt chloride paper.

Emphysema discussionIllustrations, video clips, leaflets.

Lesson 8End of Unit testPer pupil: one set of End of Unit test sheets.

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Technician Notes

496


Lesson 1Sounds are made as a result ofvibrations

Worksheet F1 Producing soundsString experiment: Three or four sonometers orstringed musical instruments.Tuning fork experiment: Three or four pairs oftuning forks, one large, one much shorter, bowlof water, wooden blocks or large corks.Metre rule experiment: Three or four metrerules.Reed experiment: Six to eight straws (persession), three or four pairs of scissors.

Lesson 2Relate changes in pitch of sounds tochanges in frequency ofvibration/Hearing range andultrasound

Demo: Hearing rangeSignal generator, connecting cables, speaker.

Lesson 3Loudness of sounds/Oscilloscoperepresentations of sounds

Demo: CROSignal generator, wires, speaker, cathode rayoscilloscope (CRO). Optional: microphone,musical instruments.

Lesson 4Model of a sound wave using aslinky/How the ear works

Demo: Sound wavesSlinky.

Worksheet F2 The earPer pupil: scissors and glue.

Lesson 5What can sound waves travelthrough?/The particle theory of themovement of sounds

Demo: Wave modelSlinky.

Worksheet F3 What can sounds travelthrough?Experiments A and CPer group: two plastic/paper cups, 2–4 m ofstring, matchstick or piece of splint.Experiment DDemo: Bell jar experimentBell jar, bell, vacuum pump, power supply forelectric bell. Optional: whale songs.

Lesson 6Calculating the speed ofsound/Speed of sound in differentmaterials/Comparison of the speedof sound and the speed of light

Worksheet F4 Planning to measure thespeed of sound

Worksheet F6 The decibel scaleOne per pupil.

Lesson 7To determine the speed of sound inair

Worksheet F5 Measuring the speed ofsound using echoesPer group: two pieces of wood, stopwatch,metre rule.

Lesson 8Noise, loudness of sounds and thedecibel scale

Demo: Measuring sound levelsDecibelmeter.

Worksheet F6 The decibel scaleOne per pupil.

Lesson 9End of Unit test

Worksheet F7 Sound wordsearchOne per pupil.Per pupil: one set of End of Unit test sheets.

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Sound and hearing


497


Lesson 1Growing micro-organisms/Differenttypes of micro-organismsStimulus material relating to the AlbertAlexander story (e.g. images).

Worksheet G2 Growing micro-organismsPer group: A sterile Petri dish containing sterilenutrient agar, marker pen to write on the Petridish, adhesive tape and scissors for sealing thedish.

Worksheet G1 Different kinds of micro-organismsOne per pupil.

Lesson 2Observe colonies of micro-organismsgrowing on agar/Investigaterespiration in yeast

Worksheet G3 Detecting respiration inyeastPer group: two test tubes, bung, tubing, limewater. Suspension of yeast in a warm glucosesolution – use about 3 g of fast-action driedyeast and 3 g of glucose in 100 cm3 of water.Petri dishes from previous lesson, plus sparecopies of Worksheet G2 Growing micro-organisms. Safe means of disposal for thedishes.

Lesson 3Using yeast to make bread andbacteria to make yoghurt

Worksheet G4 How does yeast affect breaddough?Per group (half the class): strong white breadflour, yeast suspension containing about 5 gfast-action yeast per 100 cm3 of warm water,plus a little sugar. Warm water with a littlesugar dissolved in it. Clean surface for mixingand kneading dough. 100 cm3 and 250 cm3

measuring cylinders.

Worksheet G6 Using lactose-reduced milkto make yoghurtPer group (half the class): UHT milk, UHT lactose-reduced milk, live yoghurt, measuring cylindersor syringes to measure 1 cm3 and 10 cm3, glassrod, two boiling tubes and rack, method ofmeasuring pH (preferably a probe and data-logger), water bath at 43 °C.Optional: two plastic syringes.

Worksheet G5 Investigating the effects ofdifferent concentrations of sugar on yeastrespirationOne per pupils to prepare for next lesson (ashomework).

Lesson 4A planned investigation into theeffects of sugar concentration on therate of yeast respiration

Worksheet G5 Investigating the effects ofdifferent concentrations of sugar on yeastrespirationPer group: strong white bread flour, yeastsuspension containing about 5 g fast-actionyeast per 100 cm3 of warm water, plus a littlesugar. Warm water with a little sugar dissolvedin it. Clean surface for mixing and kneadingdough. 100 cm3 and 250 cm3 measuringcylinders. Top pan balance, sucrose, glucose,spatula.Spare copies of Worksheets G3 and G4 in caseanyone has lost theirs.

Lesson 5How the body defends itself againstpathogensIf available, stimulus material such asphotographs or video clips relating to infectionand the body’s defence mechanisms againstpathogens

Worksheet G7 Food poisoningOne per pupil (for homework).

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Lesson 6Dr John Snow and the discovery ofthe cause of cholera

Worksheet G8 John Snow and the cause ofcholeraOne per pupil.

Worksheet G9 Dr Snow’s mapOne per pupil.Any other available stimulus material relating tothis story, for example video clips, images fromthe internet, photographs, portraits. Rulers andcompasses (for drawing circles on the map).

Lesson 7Immunity/The use of antibiotics andthe discovery of penicillinStimulus material (images, video clips) relatingto vaccination, and to the discovery of penicillin.

Lesson 8End of Unit testPer pupil: one set of End of Unit test sheets.

Technician Notes


Lesson 1Measuring hotness/temperatureWorksheet H1 How hot is it?Per group: Three bowls of water: one hot, onecold and one lukewarm. Mercury thermometer,paper towels.

Lesson 2Scale of temperature/Different typesof thermometerWorksheet H2 Making a scale oftemperaturePer group: Unmarked mercury thermometer,approx. 100 g of melting ice, two small rubberbands to fit tightly on stem of thermometer,beaker of boiling water, produced using, e.g.Bunsen burner, tripod, gauze, beaker, heatingmat and goggles. One piece of A4 paper. Onecalibrated mercury thermometer.

Lesson 3Direction of movement ofheat/Conductors and insulatorsDemo: Conduction and insulationSaucepan with plastic or wooden handle, largeplastic or wooden spoon, large, all-metal spoon.

Lesson 4Conduction in solids, liquids andgasesDemo: Comparison of conductivities ofmetalsCross consisting of four different metal bars, fourmarbles, candle wax.

Demo: Boiling water and iceBunsen burner, boiling tube, small ice cube, smallpiece of gauze, tongs or retort stand and clamp.

Lesson 5InsulationWorksheet H3 Keeping it hotPer group: Hot water, beaker (250 cm3),thermometer, insulation, e.g. pieces of cottonwool, fabric, sticky tape, stopwatch or clock withsecond hand, graph paper, paper towels.

Lesson 6The bimetallic stripWorksheet H4 The bimetallic stripBimetallic strip, Bunsen burner, heating mat.

Demo: The fire alarmSet up as a circuit before the lesson.Bimetallic strip, retort stand, connecting wires,power supply, electric bell.

Lesson 7Expansion of liquids and gasesDemo: Expansion of liquidBoiling tube with stopper and thin tube passingthrough stopper, oil or water, hot water bath,cold water bath.

Demo: Expansion of gasRound-bottomed flask with stopper and thintube passing through stopper, beaker of water.

Worksheet H5 The spiral experimentPer group: Piece of silver foil approx. 12 cm by 12cm, pair of scissors, 25 cm of thread, heat source,e.g. a candle, glass rod.

Demo: Density (optional)Cork, large beaker of water.

Lesson 8Convection currents in liquids andgasesWorksheet H6 Convection currents in liquidsPer group: large beaker, tripod, candle or Bunsenburner, drinking straw or narrow glass tube,spatula or tweezers, potassium manganate(VII)crystals, water.

Lesson 9Movement of heat energy byradiation/Reducing heat loss from ahomeWorksheet H7 Insulating your homeOne sheet per pupil (for homework).

Lesson 10Change of stateWorksheet H8 Cooling curve for salolPer group: Boiling tube containing hot liquidsalol, mercury thermometer, stopwatch or clockwith second hand, retort stand and clamp orlarge beaker, graph paper.

Lesson 11Review of topic ‘Heating andcooling’/Checking pupil progressPer pupil: one set of End of Unit test sheets.

CHAPTER

8

Heating and cooling


499



Lesson 1Introduction to rock structure

Worksheet I1 What are rocks made of?Several samples of different types of rocks,labelled with their names, to include limestone,granite and sandstone, distributed around theroom. Hand lenses. Containers of water intowhich rock samples can be immersed.

Lesson 2Weathering of limestone and graniteby water

Worksheet I2 How does rain causeweathering of rocks?Per group: small piece of limestone or chalk,small bottle of 0.5 mol dm–3 hydrochloric acid,with dropper, goggles.

Demo: Chemical weathering of graniteSmall pieces of granite with clearly visible grainsof feldspar, mica and quartz. Beaker containing0.5 mol dm–3 hydrochloric acid and 10 volumehydrogen peroxide, in equal volumes (sufficientto cover a piece of granite). Beaker containingwater. Digital camera and/or video cameraattached to binocular microscope if available.

Lesson 3Weathering of rock as a result oftemperature changes

Worksheet I3 How do temperature changescause weathering of rocks?

Demo: Heating and cooling rocksGranite chips 7–10 mm across, Bunsen burner,blowpipe, tongs, large beaker of cold water,goggles, safety screen.

Per group: small plastic bottle, two small pieceseach of unweathered granite and limestone,two plastic containers large enough to hold tworock pieces immersed in water; means oflabelling containers. Access to freezer. Digitalcamera or video camera attached to binocularmicroscope if available.

Demo: Chemical weathering of graniteGranite in acid and H2O2 from last lesson, tongs.Digital camera or video camera.

Lesson 4Drawing together results andexplanations of different kinds ofweatheringSpare copies of Worksheet I3 How dotemperature changes cause weathering ofrocks? Water bottles and rock samples from lastlesson.

Demo: Chemical weathering of graniteGranite in acid and H2O2 from last lesson, tongs,digital camera or video camera.

Lesson 5Introduction to erosion/The erosion,transport and deposition of rockfragments by flowing water

Demo: Chemical weathering of graniteGranite in acid and H2O2 from last lesson, tongs,digital camera or video camera.Stimulus material to introduce erosion, e.g.photographs or video clips of rivers in flood.

Worksheet I4 Investigating the transport ofrock fragments by rivers

Demo: Transport of rock fragments1 m length of square section guttering with twoend pieces. Clean sand to fill guttering to within2 cm of the top of guttering. Rubber tubing toconnect to water tap. Clip to hold tube in place.Large container to place in sink to catch sandparticles. Small quantity of coloured dye, e.g.blue ink. Gravel or pebbles.

Lesson 6Loss of mass and change in shape ofrock fragments transported by ariver

Worksheet I5 How does a river change theshape and size of rock fragments?Per group: Four expendable pieces, each about50 g, of at least one type of relatively ‘crumbly’rock, e.g. sandstone, limestone. If possible asecond type of rock, e.g. granite. Strong plasticcontainer with wide top and tightly fitting lid inwhich one set of rock pieces can be shakenaround. Access to top pan balance. Sieves ofdifferent mesh sizes.

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Technician Notes

Lesson 7Formation of sedimentary rocks bydeposition and evaporation

Worksheet I6 Making sandstonePer group: 20 cm3 plastic syringe with nozzle cutoff, smeared with petroleum jelly on the insideof the barrel, 250 g wet sand, 10 g powderedclay, 10 g plaster of Paris powder. Disposablecups and spoons for mixing. Goggles. Tray onwhich to place pellets. Masses (for testingstrength of ‘rocks’).

Worksheet I7 A story in the strataOne sheet per pupil (for homework).

Lesson 8Formation of limestone and offossils/End of Unit testPieces of limestone and chalk; samples of fossils,some still embedded in rock; photographs offossils in situ. If available, stimulus materialrelating to Mary Anning.Per pupil: one set of End of Unit test sheets.

502


Lesson 1Identifying sedimentary rocks

Worksheet J1 Identifying sedimentary rocksNamed sedimentary rocks distributed aroundthe laboratory as a circus – to include sandstone,limestone plus at least one other type. Smallbottles of dilute hydrochloric acid. Paper towelsor J cloths for wiping acid off rock samples. Adifferent example of one of the named rocktypes, labelled Rock X. Hand lenses. Goggles.

Worksheet J2 Comparing the calciumcarbonate content of two samples oflimestoneOne sheet per pupil (for homework).

Lesson 2Comparing the calcium carbonatecontent of two samples of limestoneSpare copies of Worksheet J2 Comparing thecalcium carbonate content of two samples oflimestonePer group: Two samples of different types oflimestone, with markedly different calciumcarbonate content (e.g. chalk and ironstone),each broken into small pieces. Bottle of 1 moldm–3 hydrochloric acid. Two conical flasks. Testtubes and rack. Bungs and delivery tubes for testtubes. Stop watch. Access to top pan balance.Lime water. Measuring cylinder or other methodof measuring volumes of acid. Beaker. Gassyringe. Goggles.

Lesson 3Introduction to igneous rocks/Howrate of cooling affects crystal sizeVideo clips of volcanic eruptions. Optional: videoclip of lava flowing into sea water.

Worksheet J3 How does rate of coolingaffect crystal size?Per group: Access to salol, kept at 40 °C in awater bath. A piece of rough paper, approx. A4.Two microscope slides at room temperature.Access to two microscope slides in a freezer.Access to two hand-hot microscope slides in awarm incubator. Dropper pipette. Goggles.Optional: coloured paper.

Lesson 4Apply knowledge of effect of rate ofcooling on crystal size to theappearance and formation ofdifferent types of igneous rocks

Worksheet J4 Detecting how igneous rockswere formedPer group: Samples of labelled basalt, granite,obsidian and pumice. Hand lens.Video clips of lava cooling under the sea.

Lesson 5How volcanic eruptions may affectpeople/Preparing a news reportVideo clips of damage and disruption caused bya recent volcanic eruption.

Lesson 6Metamorphic rocks

Worksheet J5 Metamorphic rocksPer group: Samples of mudstone and slate,limestone and marble. Measuring cylinders bigenough to take rock sample or Eureka can,beaker and measuring cylinder. Access to toppan balance. Hand lens.Optional: copies of the Worksheet for secondresults.

Lesson 7Interrelationships between differentkinds of rocks, and processesinvolved in their formation

Worksheet J6 What happens to fossilsduring metamorphism?Per group: Enough modelling material to makea mould. A shell that can be pressed into themodelling material. 50 g of plaster of Parispowder. An old or disposable cup for mixingplaster. Glass stirring rod.

Worksheet J7 The rock cycleOne sheet per pupil (for homework).

Lesson 8Rock identification quiz/End of UnittestSamples of at least 10 different rocks, labelledwith letters and distributed around the room(multiple samples of each rock if possible).Per pupil: one set of End of Unit test sheets.

CHAPTER

10

The rock cycle



Lesson 1Classification of vertebrates andinvertebrates, and of arthropodsLive specimens. Photographs and drawings of arange of vertebrates and invertebrates, and ofinsects, crustacea, millipedes and centipedes,and spiders. (These can be arranged around theroom and given numbers or letters, before theclass begins.)

Information sheetOne sheet per pupil (for classwork andhomework).

Worksheet K1 Classifying animalsOne sheet per pupil (for homework).

Lesson 2Classifying plants

Worksheet K2 Four groups of plantsFresh specimens of complete flowering plants,ferns and mosses. Small branches from coniferswith cones. Photographs and drawings of arange of plants belonging to these four groups.Arrange around the room, with hand lenses andbinocular microscopes if appropriate.One per pupil: Information sheet.

Worksheet K3 Classifying plantsOne sheet per pupil (for homework).

Lesson 3Communities and populations

Worksheet K4 Sampling a populationPer group: A fairly large plastic tray filled withsand. At least 30 steel tacks or ball bearings(more if possible). Square wire mesh which canbe placed on the trays to divide them into atleast 20 squares (up to 30 if possible). Barmagnets strong enough to pick up the tacksthrough sand.

Lesson 4Using random sampling to estimatepopulation size

Worksheet K5 Sampling organisms in agrassy habitatPer pupil: clipboard.

Per group: a quadrat with sides of 0.5 m. Tableof random numbers or a calculator that cangenerate them. Large tape measure or lengthsof string to act as ‘axes’ of the study area.

Worksheet K6 Comparing the daisypopulations in two habitatsOne sheet per pupil (for homework).

Lesson 5Carrying out a planned investigationinto differences in populations intwo areasPer pupil: clipboard.Per group: a quadrat with sides of 0.5 m. Tableof random numbers or a calculator that cangenerate them. Large tape measure or lengthsof string to act as ‘axes’ of the study area.Equipment for measuring environmental factorswhich can be ‘lent’ to groups as required, forexample thermometer, light meter, pH meter,hygrometer.Spare copies of Worksheet K6 Comparing thedaisy populations in two habitats.

Lesson 6Pyramids of numbersNo equipment needed.

Lesson 7Interrelationships within acommunityStimulus material, e.g. video clips, photographs,to support the literacy activity ‘Killerhedgehogs’, and video clips, photographs ofbird breeding colonies on islands.

Lesson 8Debate on solving an environmentalproblem/End of Unit testPer pupil: one set of End of Unit test sheets.

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Lesson 1What can magnets do?

Worksheet L1 A magnetic problemPer group: three similar metal bars, two ofwhich are magnets and one is steel but not amagnet.Optional: useful magnets, fridgemagnet/magnetic game.

Lesson 2Magnetic shielding and makingmagnets

Demo: Magnet and iron filingsOHT/paper, magnet, iron filings.

The hovering paper clipPer group: Thin cotton, Blu-Tack/sticky tape,magnet, paper clip, clamp stand. Access to arange of materials to place between paper clipand magnet, including a small sheet of iron orsteel.

Worksheet L2 Making magnetsPer group: steel nail, magnet, paper clips.

Lesson 3Magnetic fields

Demo: Making a compass Magnet, thin cotton, something to suspendmagnet from, e.g. wooden stool placed upsidedown.

Demo: Magnetic field around a magnetTwo magnets (in clingfilm), iron filings (inpepper pot for sprinkling).Optional: OHP, magnaprobe.

Worksheet L3 Plotting the direction of amagnetic fieldPer group: two magnets, plotting compass, ruler.

Lesson 4Electromagnets

Optional demo: ElectromagnetsElectric bell/buzzer.

Worksheet L4 Investigating electromagnetsPer group: long piece of plastic-coated wire, softiron nail, paper clips (to test strength ofelectromagnet), power pack.

Lesson 5Using electromagnets

Demo: Magnetic field around anelectromagnetLong piece of plastic-coated wire, cardboard,iron nail, power pack, iron filings.

Electromagnet postersLarge pieces of paper, coloured pencils, access tosecondary sources (CD-ROMS, books, internet).


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Framework Matching Chart

Framework Yearly Teaching Objectives for each of the Five Scientific Ideas Matchedto Absolute Science Pupil Book 2

505

Absolute Science Framework Yearly Teaching Objectives QCA SoWPupil Book 2

p. 38 Describe the role of the main nutrients in the body; 8AWhat is in food? explain why all cells need them and the importancep. 41 of a balanced diet.A balanced diet

p. 43 Explain why some nutrients have to be broken down 8AWhich nutrients before the body can use them, and use models and can be absorbed? analogies to describe how enzymes break downp. 44 large molecules during digestion.What happens to nutrients with largemolecules?

p. 45 Describe the digestive system using knowledge of 8AHow digestion enzymes to explain how it works, and the role of thehappens circulation system in transporting the products ofp. 46 digestion to cells and transporting oxygen to cells.The digestive system

p. 69 Explain that cells obtain energy through respiration, 8BHow cells get energy which often requires oxygen (aerobic respiration);p. 69 use this to explain why tissues need a good blood supply;Transporting glucose identify similarities in aerobic respiration in animals

and plants.

p. 94 Classify bacteria and fungi as cellular micro-organisms 8CWhat are micro- and viruses as micro-organisms that are smaller thanorganisms? a cell; explain that some micro-organisms are usefulp. 98 to humans and some are harmful.Harmful micro-organisms

p. 99 Describe some of the systems in the human body for 8COur natural defence fighting infecting micro-organisms, and immunisation asmechanisms a way of improving immunity; use knowledge of cells,

tissues and organs to explain how these systems work.

Cells


506


p. 150 Identify some of the main taxonomic groups of plants 8DDifferent kinds of and describe some common features.plants

Interdependence and energy

p. 154 Explain that energy is transferred between organisms in How organisms food chains and webs; use this to:depend on eachother

p. 154 – relate the abundance and distribution of organisms 8DOther ways in which to the resources made available in a habitat;organisms dependon each other.

p. 154 – begin representation of this using pyramids of 8DPyramids of numbers numbers.

Interdependence



507



Use the simple particle model to explain:

p. 43 – movement of substances through cell membranes by 8AWhich nutrients can assuming particles are of different sizes;be absorbed?

p. 141 – how crystals form and that slow cooling results in the 8HBasalt and granite formation of larger crystals from molten material and p. 142 solutions.Obsidian and pumiceWorksheet J2

Describe a more sophisticated particle model for matter, recognising:

p. 5 – the atom is the basic building block of matter; 8EAtom model

p. 4 – there are a relatively small number of different atoms; 8EAtoms and elements

p. 4 – elements consist of only one type of atom; 8EAtoms and elements

p. 4 – compounds consist of fixed combinations of different 8E, 8FAtoms and elements types of atoms that cannot be easily separated;p. 51Elements, mixturesand compounds

p. 7 – atoms and combinations of atoms can be represented 8FSymbols by symbols and formulas.

p. 11Forming new Use the more sophisticated particle model to explain 8Fcompounds by how chemical reactions take place.chemical reactions

Particles


508


Describe energy transfer as the result of temperature difference and use this to explain that:

p. 109 – heating is a process where energy is transferred; 8IWhy do things gethotter or colder?

p. 109 – temperature change is the response of the material to 8IWhy do things the energy transfer;get hotter or colder?

p. 119 – radiation is a means of energy transfer which does not 8IMovement of heat directly depend on the movement of particles.energy by radiation

Recognise that when light travels from a source it istransferring energy; use this idea to:

p. 20 – describe the nature and propagation of light; 8KHow does light travel?

p. 23 Reflection – explain the behaviour of light, including reflection and 8Kp. 26 Refraction absorption.p. 27 Dispersion

Recognise that when sound travels by vibrations fromthe source it is transferring energy; use this idea to:

p. 80 – describe amplitude and frequency; 8LFrequency of soundsp. 82Loudness

p. 84 – explain the transmission, production and reception of 8LHow does sound sound.travel?p. 85Hearing sounds

Energy



➤continued

509



p. 161 Identify magnetic materials and their properties 8JAttraction and including forces of attraction and repulsion.repulsion

p. 164 Use the idea of force to explain the patterns of magnetic 8JThe Earth’s magnetic fields produced by permanent magnets and field electromagnets.p. 165Magnetic fields

p. 165 Predict how the magnetic field pattern changes when 8JThe magnetic effect the strength of an electromagnet increases.of an electricalcurrentp. 166Electromagnets

Forces


Energy and particles

Use the particle model of solids, liquids and gases andenergy transfer to explain:

p. 110 – the process of conduction, convection and evaporation; 8IConductors andinsulatorsp. 118Convection currentsp. 113The particle modelof conduction

p. 120 – what happens when substances change state; 8IChange of state

p. 110 – the performance of thermal conductors and insulators. 8IConductors andinsulators

Energy (continued)


511

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ISBN 0 00 723594 7

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Absolute Science: Year 8 Non-specialist Teacher's Pack

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