GCSE in ADDITIONAL SCIENCE - Ysgol John Bright · 2014. 7. 28. · GCSE in ADDITIONAL SCIENCE...

GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 1

For teaching from 2011

GCSE in ADDITIONAL SCIENCE

SPECIMEN ASSESSMENT MATERIALS


Contents Page Biology

Question Paper (Foundation Tier) 5 Question Paper (Higher Tier) 21

Mark Schemes 37 Assessment Grids 51

Chemistry



Physics



Controlled Assessments 151


Candidate Name Centre Number Candidate Number

0

GCSE ADDITIONAL SCIENCE FOUNDATION TIER (Grades G-C) BIOLOGY 2 − Cells and metabolism, digestion and respiration, biodiversity SPECIMEN PAPER (1 hour)

INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces at the top of this

page. Answer all questions. Write your answers in the spaces provided in this booklet. INFORMATION FOR CANDIDATES The number of marks is given in brackets at the end of each question or part-question. You are reminded that assessment will take into account the quality of written

communication used in your answers to question 9(b).


1. Red deer have 68 chromosomes in their body cells. The diagram below shows the cell divisions which take place in red deer when

gametes are produced by meiosis.

Body cell from which gametes are made

(a) State the number of chromosomes in cell B. [1] ........................................... (b) Apart from numbers of chromosomes, give one other benefit of meiosis for

the production of gametes. [1] ...........................................................................................................................


2. Biological washing powders contain enzymes. A student carried out an investigation with a biological washing powder as follows.

Four pieces of material were stained with egg which is mainly protein and fat. Each piece of material was then soaked in a solution of the biological washing powder. The four pieces of material were left at different temperatures for 15 minutes and are shown in the diagram as they looked before and after the investigation.

(a) State three factors, other than time, which should be kept constant in this

investigation. [3] (i) ........................................................... (ii) ........................................................... (iii) .......................................................... (b) (i) From the results, which temperature would you recommend for use

with this washing powder? [1] ........................................... (ii) State the reason for your choice. [1] ............................................................................................................... ............................................................................................................... (iii) Give two ways in which you could improve the level of confidence that

this is the best temperature to use. [2] ............................................................................................................... ............................................................................................................... ............................................................................................................... .


3. The apparatus below is used to show that heat energy is produced by germinating peas.


(a) Three thermos flasks, A, B, and C, were set up as shown in the table below. The temperature of each flask was noted over 5 days.

Temperature in °C

Monday Tuesday Wednesday Thursday Friday

Flask A - live germinating peas 20.0 20.5 23.5 23.7 24.2

Flask B - dead peas 20.0 20.0 28.5 31.0 38.0

Flask C - dead, disinfected peas 20.0 20.0 20.0 20.0 20.0

(i) Explain the temperature rise in flask A. [1] ............................................................................................................... ............................................................................................................... (ii) The peas in flask B were dead so why did the temperature increase? [2] ............................................................................................................... ............................................................................................................... (b) (i) Why is it important to use a thermos or vacuum flask rather than a

glass beaker? [1] ............................................................................................................... (ii) Why was a cotton wool plug used instead of a rubber bung? [1] ...............................................................................................................


4. Green leaves of four different sizes were placed in tubes, as shown in the diagram, and left in the light. Each tube contained an equal quantity of an indicator which changes from red to purple when it becomes less acidic. The presence of carbon dioxide increases acidity.

The time taken for the indicator to change from red to purple in each tube is recorded

in the table below.

Leaf size Time taken from indicator to change from red to purple / minutes

Small 63

Medium 47

Large 26

Very large 18 (a) Explain how a biological process in the leaves caused the indicator to change

from red to purple. [3] ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................


(b) Give a reason why the indicator in the tube with the largest leaf changed colour the quickest. [1]

........................................................................................................................... (c) After 60 minutes which tube would be expected to contain the most oxygen? Underline the correct answer. [1] The tube with the: small leaf medium leaf large leaf very large leaf (d) If the apparatus was kept in the dark for several hours, which tube would

contain the most oxygen at the end of the period? [1] Underline the correct answer. The tube with the: small leaf medium leaf large leaf very large leaf


5. The diagram below shows the human respiratory system.

(a) Label parts A to C on the diagram. [3] (b) The table below shows some of the contents of inhaled and exhaled air.

Gas Inhaled air (%) Exhaled air (%)

Oxygen 20 15

Carbon dioxide 0.03 4 (i) Explain the decrease in oxygen in exhaled air. [2] ............................................................................................................... ............................................................................................................... ............................................................................................................... ............................................................................................................... (ii) Explain the increase in carbon dioxide in exhaled air. [2] ............................................................................................................... ............................................................................................................... ............................................................................................................... ...............................................................................................................


6. The kakapo is a flightless parrot found only in New Zealand. It lives and nests on the ground.

In 2002 there were 86 kakapo alive in New Zealand. They were all under the

protective care of the Department of Conservation and the kakapo was classed as extinct in the wild.

The diagram below shows the mammals introduced into New Zealand by people and how these animals interact with the kakapo.


(a) Using only the information given, state two reasons why the number of kakapo fell before they were taken into protective care. [2]

1. ...................................................................................................................... 2 ...................................................................................................................... (b) The New Zealand Department of Conservation moved all the remaining

kakapo from the mainland to carefully chosen small islands off the coast. Suggest one reason why small islands were chosen. [1]

.......................................................................................................................... .......................................................................................................................... (c) Suggest one ethical issue surrounding the conservation of the kakapo. [1] .......................................................................................................................... .......................................................................................................................... ..........................................................................................................................


7. The diagrams show two potato cylinders after they had been left for 24 hours in different solutions. At the beginning of the experiment they both looked like diagram A.

(a) Explain, in terms of water movement, why B is different to A. [4] ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (b) State how you could make the cylinder in B change back to the way it looked

at the beginning of the experiment. [1] ........................................................................................................................... ...........................................................................................................................


8. The diagram below shows the human digestive system.

(a) Label parts A and B on the diagram. [1] (b) What is meant by the term digestion? [3] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (c) Describe the digestion in the small intestine of a meal containing

carbohydrate, protein and fat. [4] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... ..........................................................................................................................


9. The activity of the enzyme carbohydrase on starch can be investigated using the following apparatus which measures the amount of light passing through the solution.

The solution in the boiling tube consisted of starch, carbohydrase and iodine. The following graph appeared on the computer screen at the end of the investigation.


(a) Iodine is used to test for starch. In the presence of starch, iodine changes colour from

..................................................... to ..................................................... [1] (b) Describe and explain the results seen in the graph by referring to the

expected colour changes and reactions taking place in the boiling tube. [6 QWC] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (c) On the graph, draw a line to show what result you would expect if boiled,

cooled carbohydrase was used with a solution of starch and iodine. [1] (d) Describe a test that you would carry out to show the end product of the

reaction taking place in the boiling tube. [2] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... ..........................................................................................................................


10. (a) Define the term biodiversity. [2] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (b) Floating pennywort is an alien plant species in Britain. It grows in slow

flowing waterways such as canals and lakes where it forms dense mats which grow at the rate of 20cm a day. Floating pennywort out-competes native plants, reduces the oxygen content of water and has a damaging effect on flood control.

(i) What is meant by an alien species? [1]

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

(ii) State one harmful effect that floating pennywort could have on native

wildlife. [1]

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


(c) In Florida, the southern army worm is known to eat floating pennywort and in Argentina there is a weevil (an insect) that only eats floating pennywort.

What advice would you give the Environment Agency about the dangers of introducing these organisms into Britain as methods of biological control against floating pennywort? [2]

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



0

GCSE ADDITIONAL SCIENCE HIGHER TIER (Grades D-A*) BIOLOGY 2 − Cells and metabolism, digestion and respiration, biodiversity SPECIMEN PAPER (1 hour)



communication used in your answers to questions 2(b) and 7.


1. The diagram below shows the human digestive system.

(a) Label parts A and B on the diagram. [1] (b) What is meant by the term digestion? [3] .......................................................................................................................... ......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (c) Describe the digestion in the small intestine of a meal containing

carbohydrate, protein and fat. [4] .......................................................................................................................... ......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... ..........................................................................................................................


2. The activity of the enzyme carbohydrase on starch can be investigated using the following apparatus which measures the amount of light passing through the solution.

The solution in the boiling tube consisted of starch, carbohydrase and iodine. The following graph appeared on the computer screen at the end of the investigation.


(a) Iodine is used to test for starch. In the presence of starch, iodine changes colour from

..................................................... to ..................................................... [1] (b) Describe and explain the results seen in the graph by referring to the

expected colour changes and reactions taking place in the boiling tube. [6 QWC] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (c) On the graph, draw a line to show what result you would expect if boiled,

cooled carbohydrase was used with a solution of starch and iodine. [1] (d) Describe a test that you would carry out to show the end product of the

reaction taking place in the boiling tube. [2] .......................................................................................................................... .......................................................................................................................... …....................................................................................................................... ..........................................................................................................................


3. (a) Define the term biodiversity. [2] .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (b) Floating pennywort is an alien plant species in Britain. It grows in slow

flowing waterways such as canals and lakes where it forms dense mats which grow at the rate of 20cm a day. Floating pennywort out-competes native plants, reduces the oxygen content of water and has a damaging effect on flood control.

(i) What is meant by an alien species? [1]

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

(ii) State one harmful effect that floating pennywort could have on native wildlife. [1] ............................................................................................................... ...............................................................................................................


(c) In Florida, the southern army worm is known to eat floating pennywort and in Argentina there is a weevil (an insect) that only eats floating pennywort.

What advice would you give the Environment Agency about the dangers of introducing these organisms into Britain as methods of biological control against floating pennywort? [2]

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


4. Tendons are tissues that attach muscles to bones. Recent treatment of sports horses with leg tendon injuries involves the injection of

stem cells into the tendon. Stem cells from bone marrow behave like embryonic stem cells.

Bone marrow is obtained from the breastbone of the horse and sent to a laboratory where the stem cells are cultured (grown).

After 48-72 hours the stem cells are injected into the injured tendon. This process is shown below.

(a) What are stem cells? [1] ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................


(b) The photograph below shows ultrasound scans of an injured leg tendon of a horse before and after stem cell treatment.

Explain how the stem cells have helped to repair the tendon. [1] ........................................................................................................................... ........................................................................................................................... (c) The use of human embryonic stem cells is regulated because this kind of

stem cell comes from human embryos. Why are many people concerned about using stem cells from human embryos whilst others are in favour.

Give one reason for using embryos and one reason against. [2] ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................


5. Maple leaves were analysed for their sugar and starch content over a 24 hour period. The data, together with the light intensity readings, are shown in the chart below.

Time

(a) State the relationship between light intensity and starch production. [1] ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (b) Sugar and starch are products of photosynthesis. Suggest why the level of

sugar in the leaf is highest at night. [1] ............................................................................................................... ............................................................................................................... ...............................................................................................................


(c) (i) Choose the time you would expect to find the highest concentration of oxygen in the air at the surface of the leaf.

Tick ( ) one box only. [1]

Time Tick

Midnight

4 am

8 am

12 Noon

4 pm

8 pm (ii) Explain your answer. [3] ............................................................................................................... ............................................................................................................... ............................................................................................................... ...............................................................................................................


6. The following experiment was carried out to show the effect of ethanol (alcohol) on yeast when it fermented glucose anaerobically.

The sterile syringes were prepared as shown in the diagram and left for 1 hour. At the end of the hour, the distance the liquid in the glass tube moved in each syringe was measured.

(a) Explain (i) why the liquid moved in the glass tube; [2] ............................................................................................................... ............................................................................................................... ............................................................................................................... (ii) why the temperature in syringe 1 was higher than that in syringe 2 at

the end of one hour; [2] ............................................................................................................... ............................................................................................................... ............................................................................................................... (iii) why it is important to use sterile syringes. [1] ............................................................................................................... ...............................................................................................................


(b) The results of the experiment were as follows:

Time (min) Distance moved by liquid in the glass tube (mm)

Syringe 1 Syringe 2

0 0 0

40 30 10

50 100 16

60 220 20 Suggest an explanation of the results. [1] ........................................................................................................................... ...........................................................................................................................


7. The following advert for Joy's cigarettes appeared in a newspaper more than 100 years ago.

This advert would not appear in modern newspapers. Describe how and why

attitudes to smoking have changed. [6 QWC] ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... .......................................................................................................................................


8. The first contact lenses to be developed were made of glass. The diagram shows what happened when a glass contact lens was put on the eye.

These lenses proved to be unsuitable because they caused pain. (a) The diagram shows water entering the cornea of the eye by osmosis. Define osmosis. [2] ........................................................................................................................... ........................................................................................................................... (b) Modern contact lenses are gas permeable. Use the information in the diagram to explain why these modern contact

lenses are more suitable than glass contact lenses. [4] ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ………................................................................................................................


9. There are several methods of sampling animals or plants in their natural habitats. (a) State two limitations of random sampling methods. [2] ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (b) During an investigation into numbers of trout in a lake, a method of capturing

the trout, marking them with a harmless dye, and then recapturing them was used.

(i) In this investigation, what data would you need to record and how

could it be used to estimate the size of the trout population? [4]

............................................................................................................... ............................................................................................................... ............................................................................................................... ............................................................................................................... ............................................................................................................... ............................................................................................................... ............................................................................................................... ............................................................................................................... (ii) When using such a capture-recapture technique to estimate

population size, what assumptions are being made about (I) the effect of marking individuals; [1] ............................................................................................................... ............................................................................................................... (II) movement of individuals into the area studied? [1] ............................................................................................................... ...............................................................................................................


MARK SCHEMES


General Marking Instructions 1. Over-rigidity in the interpretation of the mark scheme is not intended and it is

accepted that points may be made in a variety of different ways including converse and counterpoints.

2. Phonetic spelling is allowed except where there is a possibility that scientific terms

might be confused. 3. When candidates list alternative answers to short answer questions, the general

principle to be followed is: right + wrong = no mark. In a question requiring a set number of responses, where a candidate has supplied extra responses above the required number each error/contradiction negates one correct response, however responses considered neutral (ie not incorrect) are not penalised.

4. The principle of error carried forward is generally applied where an incorrect value

calculated in one part of a question is treated as being correct for the purposes of subsequent parts.

5. When marking calculations, substitution into an incorrect equation is not credited and

hence subsequent calculations within that section will score zero. 6. Alternative answers are accepted even if not noted on the marking scheme as long

as they are appropriate, correct and valid in the context of the science. Note that in some cases specific terms are a requirement. Any uncertainty about the acceptability of an answer is clarified by consultation with the Principal examiner or Team Leader.

7. Marking Quality of Written Communication: The marking scheme for these questions

includes indicative content which gives the outline of the content of a good answer. Candidates should generally cover most, if not quite all, of the points in the indicative content to achieve the highest mark band on these questions and if candidates present alternative valid approaches these are equally acceptable. The tests to be applied are coherence, which is expressed well scientifically, as well as completeness and correct science at an appropriate level.

8. Abbreviations used in marking schemes: / = alternative points c.e. = consequential error not: = unacceptable answer(s) allow: = not an ideal answer but considered just worthy of credit on this

occasion (un)qual(ified) = only acceptable as (part of) an answer if extra detail or

explanation is provided AVP = any valid point owtte = or words to that effect reference to… = implies that these general ideas are required although they may

be expressed differently or made using different terminology and in a different sequence.


Additional Science - Biology 2 Marking Scheme

Foundation Tier 1. (a) 34 [1] (b) genetic composition of daughter cells is not identical to mother cell/ owtte [1] Question total [2] 2. (a) same material concentration of solution/volume or quantity of powder or enzyme or water; pH/acidity/alkalinity quantity/thickness/area of stain [3] (Any 3) (b) (i) 35oC [1]

(ii) most stain removed (not: ref. optimum /works best at this temperature) [1] (iii) Reference to taking repeat readings [1] Reference to need to test temperatures between 35oC and 80oC. [1]

Question total [7] 3. (a) (i) the peas are carrying out respiration and so are giving off heat [1] (ii) decomposers/bacteria/fungi are present [1] and are respiring/giving off heat [1] (b) (i) to retain heat/ owtte [1] (ii) to allow gases to diffuse/because oxygen is needed for respiration [1] Question total [5]


4. (a) Two marks can be awarded for two correct and relevant points e.g. photosynthesis (is taking place) [1]

which removes / absorbs / uses CO2 [1] (not: ref. to respiration)

The third mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g.

so less acidity / more alkaline/owtte. [1] (b) it uses / absorbs / takes most CO2 /carries out most photosynthesis/takes in

CO2 fastest [1] (not: more) (c) very large leaf [1] (d) small leaf [1] Question total [6] 5. (a) A. rib [1] B. bronchus [1] C. alveolus [1] (b) (i) One mark can be awarded for a correct and relevant point e.g.

oxygen diffuses from alveoli/ lung [1] The second mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g.

into blood so less is in air breathed out [1] (allow: used for (1) respiration (1)) (ii) One mark can be awarded for a correct and relevant point e.g.

carbon dioxide diffuses from blood [1] The second mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g. into alveoli/lung so more is in air breathed out [1]

(allow: CO2 produced (1) in respiration (1)) Question total [7] 6. (a) eaten/killed by rat / stoat [1] Its food is eaten by possum / deer / rabbit [1] (not: competition unqualified) (b) easier to remove all the predators / competitors could be kept out/AVP [1] (c) Conflict between man and animals for land Land used for crops so loss of habitat Removing other animals from island to make way for kakapo Shouldn’t be allowed to die out as may be useful in the future Loss of biodiversity / AVP [1] Question total [4]


7. (a) Three marks can be awarded for three correct and relevant points e.g. water passes out of the cells (not: ref. to solution or liquid) [1]

from high water potential to low or correct description e.g. from where it is in high concentration to where it is in low concentration/water passes

down a concentration gradient [1] through a selectively permeable membrane [1]

The fourth mark can only be awarded if the candidate coherently and correctly links the consequence to the points above e.g.

this causes a loss of support/potato becomes less firm /flaccid/becomes soft so it bends [1] (b) put it in water/weaker solution (allow: add water) [1] Question total [5] 8. (a) A pancreas B large intestine [1] (b) process which breaks down/changes; [1] large insoluble molecules into small/soluble substances; [1] so they can be absorbed. [1] (c) carbohydrates/starch (to glucose*) by carbohydrases/amylase [1] proteins (to amino acids*) by proteases [1] fats (to fatty acids & glycerol*) by lipases [1] Any 1 of 3 products* from correct substrate [1] Question total [8]


9. (a) (light) brown/yellow to dark/blue-black/black (not: blue) [1]

(b) Indicative content:

The starch is digested/broken down by the carbohydrase /amylase to sugar/maltose/glucose. As iodine is dark blue/black in the presence of starch the amount of light passing through at the start is low. As the enzyme acts the colour changes from dark blue to lighter/blue/brown as the starch is broken down. The colour/ colour density changes shown on the graph therefore shows more light passing through as the colour changes. 5 – 6 marks The candidate constructs an articulate, integrated account

correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar.

3 – 4 marks The candidate constructs an account correctly linking some

relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar.

1 – 2 marks The candidate makes some relevant points, such as those in

the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar.

0 marks The candidate does not make any attempt or give a relevant

answer worthy of credit. [6]

(c) Straight horizontal line starting where line on graph starts and continuing to near end of axis [1] (d) Add Benedict’s [1] Boil/heat STRONGLY/heat to any stated temperature 80°C/boiling water bath [1] (not: warm/heat gently or just heat) Question total [10]


10. (a) The variety or number [1] of different species in an area [1] (not: the number of organisms) (b) (i) A (non-native) species introduced into a country/habitat. owtte e.g.

an organism introduced into another country where it is not normally found. (human involvement implied) (not: a non-native species unqual.) [1]

(ii) Answers relating to a reduction in native plant species due to

competition/ reduction in oxygen content in water could kill or eq. aquatic insects/fish/plants. [1]

(c) Reference to the biological control agents eating/destroying native/other

plants/species/ref. introduce disease/ introduce weevil as it only eats floating pennywort. [1] Reference to biological control agents becoming pests themselves/no native

predator so it breeds and gets out of control or reduces biodiversity [1] (not: ref. to could outcompete native species). Question total [6]


Additional Science - Biology 2 Marking Scheme

Higher Tier 1. (a) A pancreas B large intestine [1] (b) process which breaks down/changes; [1] large insoluble molecules into small/soluble substances; [1] so they can be absorbed. [1] (b) carbohydrates/starch (to glucose*) by carbohydrases/amylase [1] proteins (to amino acids*) by proteases [1] fats (to fatty acids & glycerol*) by lipases [1] Any 1 of 3 products* from correct substrate [1] Question total [8] 2. (a) (light) brown/yellow to dark/blue-black/black (not: blue) [1]

(b) Indicative content:

The starch is digested/broken down by the carbohydrase /amylase to sugar/maltose/glucose. As iodine is dark blue/black in the presence of starch the amount of light passing through at the start is low. As the enzyme acts the colour changes from dark blue to lighter/blue/brown as the starch is broken down. The colour/ colour density changes shown on the graph therefore shows more light passing through as the colour changes.

5 – 6 marks The candidate constructs an articulate, integrated account correctly

linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar.

3 – 4 marks The candidate constructs an account correctly linking some relevant

points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar.

1 – 2 marks The candidate makes some relevant points, such as those in the

indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar.

0 marks The candidate does not make any attempt or give a relevant answer

worthy of credit. [6]

(c) Straight horizontal line starting where line on graph starts and continuing to

near end of axis [1] (d) Add Benedict’s [1] Boil/heat STRONGLY/heat to any stated temperature 80°C/boiling water bath [1] (not: warm/heat gently or just heat) Question total [10]


3. (a) The variety or number [1] of different species in an area [1] (not: the number of organisms) (b) (i) A (non-native) species introduced into a country/habitat. owtte e.g.

an organism introduced into another country where it is not normally found. (human involvement implied) (not: a non-native species unqual.) [1]

(ii) Answers relating to a reduction in native plant species due to

competition/ reduction in oxygen content in water could kill or eq. aquatic insects/fish/plants. [1]

(c) Reference to the biological control agents eating/destroying native/other

plants/species/ref. introduce disease/ introduce weevil as it only eats floating pennywort. [1]

Reference to biological control agents becoming pests themselves/no native

predator so it breeds and gets out of control or reduces biodiversity [1] (not: ref. to could out compete native species). Question total [6] 4. (a) Unspecialised/undifferentiated cells that can develop into other cells [1] (b) Stem cells have 'changed'/differentiated into tendon cells which have

replaced the damaged tissue. [1] (not: tendons) (c) Reference to: concerns about use of human embryos in experimental work

because embryos are destroyed after 14 days/ethical/religious concerns about using embryos that have the ability to develop into humans; [1]

can be used to cure disease by targeting areas specifically/limited side effects

compared to drugs. [1] Question total [4]


5. (a) Increase in light intensity gives an increase in starch production (or converse). [1]

(b) Starch is turned to sugar at night as photosynthesis is not taking place. [1] (c) (i) (12) noon. [1] (ii) Two marks can be awarded for two correct and relevant points e.g.

oxygen is produced by photosynthesis [1] from the graph most light/maximum light is at noon [1]

The third mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g.

therefore maximum rate of photosynthesis and oxygen production is at noon [1] Question total [6] 6. (a) (i) carbon dioxide produced which [1] exerted pressure/pushed it down (not: ref. to volume) [1] (ii) more energy/heat is being released/produced [1] by respiration [1] (iii) microbes/bacteria would use glucose/respire [1] (b) (ethanol) acts as a poison/kills yeast [1]

(not: stops yeast working) Question total [6]


7. Indicative content: The advert encouraged people to smoke by promising relief from some illnesses/conditions; however, the links between smoking and some illnesses are now recognised and scientifically understood e.g. tar and cancer, infections due to mucus accumulation as the cilia no longer function. It is also known that there is addiction due to nicotine. The beneficial claims in the advertisement are now known to be untrue e.g. relief of asthma/doesn’t cure diseases and doesn’t cause influenza. As a result of recent knowledge about such health issues, there has been a change in attitudes to smoking e.g. less smoking now/people trying to give up/ smoking socially unacceptable/less advertising now / less sponsorship. There is now more active discouragement and more regulation e.g. warnings on packets/restriction on under-age sales/smoking-free zones imposed by law/ ban in public places.

5 – 6 marks The candidate constructs an articulate, integrated account correctly

linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar.

3 – 4 marks The candidate constructs an account correctly linking some relevant

points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar.

1 – 2 marks The candidate makes some relevant points, such as those in the

indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar.

0 marks The candidate does not make any attempt or give a relevant answer

worthy of credit. Question total [6]


8. (a) Movement of water from where it/water is in high concentration to where it/water is in low concentration/or down a concentration gradient [1]

(allow: correct references to solutes) Through a selectively permeable membrane [1] (b) One mark can be awarded for a correct and relevant point e.g.

modern lenses allow oxygen to pass through/reach cornea so allows respiration to continue aerobically [1]

Mark points 2, 3 and 4 can only be awarded if the candidate coherently and correctly links the consequences e.g.

therefore no build up/production of lactic acid occurs (not: anaerobic respiration) [1]

so no/little osmosis/less water entering cornea [1] which means there is no pressure build up (not: ref. pain) [1] (not: water can’t get through glass) Answer only to refer to why modern lenses are suitable i.e. no reverse

argument Question total [6] 9. (a) Does not account for clumping / may miss a species / some areas left

unsampled or sampled more than once. (Any 2) [2] (b) (i) Record: the number of trout captured and marked in the first sample/

initially; (x) [1] the total number of trout caught in the second sample/recaptured; (y) [1] the number of trout recaptured/in the second sample which were marked. (z) [1] Appropriate formula for calculating estimate of population e.g. x × y [1] z

(ii) (I) Marking does not affect or make animals more conspicuous

to predators / does not affect chances or probability of being caught [1]

(II) It assumes that immigration rate is same as/balanced by emigration rate [1]

Question total [8]


ASSESSMENT GRIDS

GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 53 MARK SPECIFICATION GRID

Additional Science - Biology 2

Specimen assessment

FOUNDATION TIER

B2- Cells and metabolism, digestion and respiration, biodiversity

Assessment Objective Total Mark

AO1 AO2 AO3 Target Totals for

Paper 24 24 12 60 HSW QWC

Question Number

Specification Reference

1. (a) 1 (l) (m) 1 2 (b) 1 2. (a)

1 (i)

3

7

(b) (i) 1 (ii) 1 (iii) 2 3. (a) (i)

4 (a)(b)

1

5

(ii) 2 (b) (i) 1 (ii) 1 4. (a)

3 (b)(c)

1 2

6

(b) 1 (c) 1 (d) 1 5. (a)

6 (a) (d) 3

7

(b) (i) 1 1 (ii) 1 1 6. (a)

7 (d) (e) 2

4

(b) 1 (c) 1 7. (a)

2 (d) (e) 2 2

5

(b) 1 8. (a)

5 (d) (e) 1

8

(b) 3 (c) 3 1 9. (a)

5 (b) (d)

1

10

(b) 2 3 1 (c) 1 (d) 1 1 10. (a)

7 (d) (e)

2

6

(b) (i) 1 (ii) 1 (c) 1 1 Raw Totals: 25 24 11 60

GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 54 MARK SPECIFICATION GRID

Additional Science - Biology 2

Specimen assessment

HIGHER TIER

B2- Cells and metabolism, digestion and respiration, biodiversity


AO1 AO2 AO3 Target Totals for

Paper 24 24 12 60 HSW QWC

Question Number


1. (a) 5(d) (e)

1 8

(b) 3 (c) 3 1 2. (a)

5(b) (d)

1

10

(b) 2 3 1 (c) 1 (d) 1 1 3. (a)

7(d) (e)

2

6

(b) (i) 1 (ii) 1 (c) 1 1 4. (a)

1(o) 1

4

(b) 1 (c) 1 1 5. (a) (i)

3 (b) (c) (d), 1(d)

1

6

(b) 1 (c) (i) 1 (ii) 2 1 6. (a) (i)

4(d), 1(h)

1 1

6

(ii) 1 1 (iii) 1 (b) 1 7. 6(f), (g) 2 3 1 6 8. (a)

2(b) (e), 4(c) (d) 2

6

(b) 3 1 9. (a)

7(c) 2

8

(b) (i) 3 1 (ii) 1 1 Raw Totals: 26 23 11 60



0

GCSE ADDITIONAL SCIENCE FOUNDATION TIER (Grades G-C) CHEMISTRY 2 – Atoms, bonding and chemical change SPECIMEN PAPER (1 hour)



communication used in your answer to question 8(a).


Answer all questions.

1. (a) Soap solution was shaken with four different water samples. The results are shown in the diagram below.

(i) Complete the bar chart of the results on the grid below. [2]


(ii) Complete the following sentences. I The hardest water is in sample ........................................... [1] II The softest water is in sample ............................................ [1] (iii) I Using the information in the diagram opposite, state one

factor which was controlled in order to make the investigation a fair test. [1]

............................................................................................. II State one other factor which you would choose to keep

constant if you were planning to repeat the investigation. [1] ............................................................................................. (b) (i) Choose, from the box below, the metal ions that cause hardness when

present in water. [1]

calcium iron sodium

.............................................................................. (ii) State one advantage of hard water. [1] .....................................................................................................................


2. (a) The diagram below shows an atom of lithium.

(i) Use the numbers in the box below to answer parts (i) I and II. Give the I atomic number of lithium, ................................................ [1] II mass number of lithium. .................................................. [1] (ii) Complete the following sentences. I Protons and ...................................... are always found in

equal numbers in atoms. [1] II Protons and ....................................... have equal masses. [1] (b) Calculate the relative molecular mass (Mr) of ammonia, NH3. [2]

Ar(N) = 14 Ar(H) = 1

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

1 2 3 4 7


3. (a) Substances can be classified as

metallic ionic simple molecular giant covalent

Use the types of substance named above to complete the following sentences.

(i) Carbon dioxide is a gas at room temperature due to it being ...................................................................................................... [1] (ii) Sodium chloride conducts electricity when in solution due to it being ....................................................................................................... [1] (b) The following diagram shows the structure of a metal.

(i) Using the diagram, complete the following sentence to explain why metals are good conductors of electricity. [2]

When a metal is connected to a battery .................................... move across the structure towards the ............................................................ (ii) State one property of a metal that can be explained by the fact that

the positive ions can slide over each other. [1] .............................................................................................................. (c) The following diagrams, A, B and C, show the structures of methane, graphite

and diamond but not necessarily in that order. [2]

Label each diagram with the correct name.

A ........................ B ........................ C ........................


4. (i) The box below shows some smart materials.

thermochromic materials photochromic materials shape memory alloys

hydrogels shape memory polymers

Choose from the box the type of smart materials that I are used to make lenses for sunglasses, [1] ……………………………………………………………………………………. II swell up to 1000 times in volume when added to water. [1] …………………………………………………………………………………….

(ii) Nitinol and steel are both alloys. Nitinol is a shape memory alloy but steel is not.

Sian made coils from straight lengths of nitinol and steel wires and gave both

to Kieran. Describe what Kieran should do to find out which is which, stating the

observations for both wires. [2] ……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………….


5. This question is about the reactions of potassium. (i) State why potassium is stored in bottles of paraffin oil. [1] ......................................................................................................... (ii) I Complete the following risk assessment which the teacher

carried out before demonstrating the reaction of potassium with water. [2]

Hazard Precaution

handle with tongs

molten potassium splatters and lands on student's skin

II The following diagram shows what happens when potassium

reacts with water.

Name gas G. ....................................................................... [1]

(iii) Complete and balance the symbol equation for the reaction of potassium and chlorine to form potassium chloride. [2]

2K + Cl2 ..............

water

gas G flame

potassium


6. (a) Ravinder is given three solutions, labelled A, B and C. He carries out tests to identify the compound present in each. The results of the tests are shown below.

Test

Solution Flame test Addition of silver nitrate

A crimson flame cream precipitate

B orange-yellow flame white precipitate

C lilac flame yellow precipitate

Use these results to identify the compound present in each solution. [3] A ............................................................. B ............................................................. C ............................................................. (b) Jo found that each of her solutions gave a yellow precipitate when silver

nitrate was added. Suggest how this may have happened and any possible steps that could be

taken to ensure that the same did not occur on repeating the tests. [2] ……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………….


7. The graph below shows the solubility of potassium nitrate in water at different temperatures.

(i) The table below shows the solubility of potassium bromide in water at

different temperatures. The solubility at 60 °C is missing from the table.

Temperature / ºC 0 10 20 30 40 50 60 70 80

Solubility / g per 100 g water 54 58 64 70 76 82 92 98


I Draw the graph of the solubility of potassium bromide on the grid overleaf. Two points have been plotted for you. [2]

II Use the graph to give the solubility of potassium bromide at 60 °C. [1] …………………….. g per 100 g water III Give the temperature at which the two compounds have the same

solubility. [1] ……………………. °C IV Describe the trend in the solubility of potassium bromide and how it

differs from that of potassium nitrate. [2] ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. (ii) I Emmanuel tested the solubility of a lithium compound in water at a

range of temperatures from 20 to 60 °C. He was surprised to see that the solubility appeared to decrease as

the temperature of the water increased. Suggest what he should do before reporting his results to his teacher. [1] ………………………………………………………………………………. II Give a reason why Emmanuel decided to measure and record the

solubility of this compound to the nearest 0.1 g per 100 g water. [1] ……………………………………………………………………………………. …………………………………………………………………………………….

Temperature / °C

20 30 40 50 60

Solubility / g per 100 g water

34.8 34.2 33.7 33.2 32.6


8. (a) A chlorine atom contains 17 negatively charged electrons in orbit around its nucleus as shown in the following diagram.

Explain why a chlorine atom has no overall charge and describe the link

between its electronic structure and its position in the Periodic Table. [6 QWC] ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………….

(b) Chlorine has two isotopes – chlorine-35 and chlorine-37. State what is meant by the term isotopes. [1]

……………………………………………………………………………………. …………………………………………………………………………………….


9. Jan and Gareth investigated how the temperature of hydrochloric acid affected the rate of its reaction with marble chips.

They added identical amounts of marble chips to samples of acids with different temperatures and measured the time taken to collect 50 cm3 of carbon dioxide gas. (a) Their results are shown in the following table.

Time taken to collect 50 cm3 of gas / seconds

Temperature of acid / °C

1 2 3 Mean

20 75

68 71

30 48

49 47

40 50

32 34

50 19

17 15

60 8

10 9

(i) Each experiment was performed 3 times in order to find out whether

or not the results are ‘repeatable’. Identify one result from the table which should be checked e.g. by repeating the experiment once more. [1]

……………………………………………………………………………. (ii) Suggest one possible explanation for this particular reading. [1] ……………………………………………………………………………. …………………………………………………………………………….


(iii) Calculate the mean values for the time taken to collect 50 cm3 of gas at each different temperature. [2]

……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. (b) State the conclusion that Jan and Gareth should draw from the evidence they

have collected. [1] ……………………………………………………………………………………. ……………………………………………………………………………………. (c) Another pair of students chose to investigate the effect of acid concentration

on the rate of reaction. (i) They were given acid of concentration 2.0 M to be diluted to prepare

solutions of lower concentrations. Suggest suitable acid concentrations for them to use in their investigation. [2]

…………………………………………………………………………. …………………………………………………………………………. …………………………………………………………………………. (ii) They found that the reaction proceeded more quickly as the

concentration increased. Explain why this is the case using particle theory. [2]

…………………………………………………………………………. …………………………………………………………………………. ………………………………………………………………………….


FORMULAE FOR SOME COMMON IONS

POSITIVE IONS NEGATIVE IONS

NAME FORMULA NAME FORMULA

Aluminium Al3+ Bromide Br-

Ammonium NH4+ Carbonate CO3

2-

Barium Ba2+ Chloride CI-

Calcium Ca2+ Fluoride F-

Copper(II) Cu2+ Hydroxide OH-

Hydrogen H+ Iodide I-

Iron(II) Fe2+ Nitrate NO3-

Iron(III) Fe3+ Oxide O2-

Lithium Li+ Sulfate SO42-

Magnesium Mg2+

Nickel Ni2+

Potassium K+

Silver Ag+

Sodium Na+



0

GCSE ADDITIONAL SCIENCE HIGHER TIER (Grades D-A*) CHEMISTRY 2 – Atoms, bonding and chemical change SPECIMEN PAPER (1 hour)



communication used in your answer to questions 2(a) and 8(a).


1. The graph below shows the solubility of potassium nitrate in water at different temperatures.

(i) The table below shows the solubility of potassium bromide in water at

different temperatures. The solubility at 60 °C is missing from the table.

Temperature / ºC 0 10 20 30 40 50 60 70 80

Solubility / g per 100 g water 54 58 64 70 76 82 92 98


I Draw the graph of the solubility of potassium bromide on the grid opposite. Two points have been plotted for you. [2]

II Use the graph to give the solubility of potassium bromide at 60 °C. [1] …………………….. g per 100 g water III Give the temperature at which the two compounds have the same

solubility. [1] ……………………. °C IV Describe the trend in the solubility of potassium bromide and how it

differs from that of potassium nitrate. [2] ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. (ii) I Emmanuel tested the solubility of a lithium compound in water at a

range of temperatures from 20 to 60 °C. He was surprised to see that the solubility appeared to decrease as

the temperature of the water increased. Suggest what he should do before reporting his results to his teacher. [1] ………………………………………………………………………………. II Give a reason why Emmanuel decided to measure and record the

solubility of this compound to the nearest 0.1 g per 100 g water. [1] ……………………………………………………………………………………. …………………………………………………………………………………….

Temperature / °C

20 30 40 50 60

Solubility / g per 100 g water

34.8 34.2 33.7 33.2 32.6


2. (a) A chlorine atom contains 17 negatively charged electrons in orbit around its nucleus as shown in the following diagram.

Explain why a chlorine atom has no overall charge and describe the link

between its electronic structure and its position in the Periodic Table. [6 QWC] ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………….

(b) Chlorine has two isotopes – chlorine-35 and chlorine-37. State what is meant by the term isotopes. [1]

……………………………………………………………………………………. …………………………………………………………………………………….


3. Jan and Gareth investigated how the temperature of hydrochloric acid affected the rate of its reaction with marble chips.

They added identical amounts of marble chips to samples of acids with different

temperatures and measured the time taken to collect 50 cm3 of carbon dioxide gas. (a) Their results are shown in the following table.

Time taken to collect 50 cm3 of gas / seconds

Temperature of acid / °C

1 2 3 Mean

20 75

68 71

30 48

49 47

40 50

32 34

50 19

17 15

60 8

10 9

(i) Each experiment was performed 3 times in order to find out whether

or not the results are ‘repeatable’. Identify one result from the table which should be checked e.g. by repeating the experiment once more. [1]

……………………………………………………………………………. (ii) Suggest one possible explanation for this particular reading. [1] ……………………………………………………………………………. …………………………………………………………………………….


(iii) Calculate the mean values for the time taken to collect 50 cm3 of gas at each different temperature. [2]

……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. (b) State the conclusion that Jan and Gareth should draw from the evidence they

have collected. [1] ……………………………………………………………………………………. ……………………………………………………………………………………. (c) Another pair of students chose to investigate the effect of acid concentration

on the rate of reaction. (i) They were given acid of concentration 2.0 M to be diluted to prepare

solutions of lower concentrations. Suggest suitable acid concentrations for them to use in their investigation. [2]

…………………………………………………………………………. …………………………………………………………………………. …………………………………………………………………………. (ii) They found that the reaction proceeded more quickly as the

concentration increased. Explain why this is the case using particle theory. [2]

…………………………………………………………………………. …………………………………………………………………………. ………………………………………………………………………….


4. (a) A forensic scientist has recovered an ink sample from the scene of a crime and wants to compare it with samples found in the possession of three suspects.

She finds that the recovered ink has an Rf value of 0.7.

Use the information in the following chromatogram and the formula given to

discover which, if any, of the inks match that from the crime scene. You must show your working. [2]

solvent theby travelled distanceink theby travelled distance value Rf =

……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………….

(b) (i) Simple compounds containing potassium can be identified using a flame test.

State the flame colour seen when potassium chloride is heated in a blue flame. [1]

…………….......………………………………………………………………

(ii) Name a technique that could be used to identify and measure the

amount of potassium present in biological tissue. [1]

…………….......………………………………………………………………

6

5

4

3

2

1

0 cm

A B C

solvent front


5. (a) Magnesium reacts with oxygen to form magnesium oxide. (i) Using the electronic structures given below, show by means of a

diagram the electronic changes that take place during the formation of magnesium oxide. Show the charges on the ions formed. [3]

magnesium = 2,8,2 oxygen = 2,6 (ii) State why magnesium oxide is a high melting point solid. [1] .............................................................................................................. . .............................................................................................................. (b) The diagram below shows the type of bonding present in methane, CH4.

(i) Name this type of bonding. ............................................................ [1] (ii) The bonds within the molecule are very strong. Despite this, methane

has a low boiling point. State why this is the case. [1]

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


(c) The structures of diamond and graphite are shown below.

Give the reason why

(i) diamond is hard, [1] ................................................................................................................ ................................................................................................................ (ii) graphite can be used as a lubricant. [1] ................................................................................................................ ................................................................................................................


6. This question is about the halogens and the halides – the elements of Group 7 and their compounds.

(a) When bromine water is added to a solution of sodium iodide, a brown solution

is formed showing that a reaction has occurred. No reaction occurs when bromine water is added to a solution of sodium chloride.

(i) Explain this difference in terms of the relative reactivities of the

halogens. [1] ................................................................................................................ ................................................................................................................ (ii) Balance the following chemical equation for the reaction that takes

place between bromine water and sodium iodide. [1] Br2 + NaI → NaBr + I2

(b) Sodium bromide and sodium iodide can also be distinguished from one another by their reaction with silver nitrate solution.

Give the expected observation for one of the reactions, stating clearly to which one it refers. [1]

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

(c) Write an ionic equation for the reaction of silver ions and chloride ions. [1]

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


7. Steve and Justin carried out an investigation to find the relative hardness of four water samples, A, B, C and D. They added soap solution to each sample, shook the mixtures and recorded the time taken for the lather to disappear.

Their results are as follows.

Time for lather to disappear / s

Test 1 Test 2

A 310 300

B 400 410

C 30 30

D 90 100 (i) Giving a reason for your answer, state which water sample is the hardest. [1] ……………………………………………………………………………………. (ii) Three other groups carried out similar investigations and they recorded their

results in the same table.

Time for lather to disappear / s

Group 1 Group 2 Group 3

A 180 250 80

B 220 400 100

C 20 40 10

D 80 100 20 State to what extent these results confirm your conclusion in (i). Suggest a possible reason for the difference between each group’s results. [2] ……………………………………………………………………………………. ……………………………………………………………………………………. …………………………………………………………………………………….

(iii) State which ions, in addition to calcium ions, cause hardness in water. [1]

…………………………………………………………………………………….


8. (a) Explain how crude oil is separated into different fractions. [6 QWC] ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. (b) When ethene, C2H4, burns in air, carbon dioxide and water are formed as

shown in the following equation. C2H4 + 3O2 2CO2 + 2H2O

The relative amounts of energy needed to break the bonds in the reactants are shown in the table below.

Bond

Amount of energy needed to break bond / kJ

C = C

612

C – H

413

O = O

496


(i) Use these values to calculate the relative energy (in kJ) needed to break all the bonds in the reactants. [2]

………………………………………………………………………………. ………………………………………………………………………………. (ii) 4828 kJ of energy are released when new bonds are formed in the

products. Calculate the overall energy change for the reaction. [1] ……………………………………………………………………………….


9. (a) Smart materials have unusual properties. Describe the unusual property that (i) smart alloys show on heating, [1] .......................................................................................................... (ii) thermochromic materials show on heating. [1] .......................................................................................................... (b) The most effective and widely used smart alloy is nitinol which contains 50 %

titanium. Titanium, Ti, is a metal which is extracted from ores containing titanium(IV)

oxide. This oxide is converted into titanium(IV) chloride, TiCI4, which is then reacted with either sodium or magnesium to form titanium metal. The equation below shows the formation of titanium from titanium chloride using sodium.

TiCI4 + 4Na Ti + 4NaCI

Ar(Na) = 23 Ar(Ti) = 48

(i) Use the equation above to calculate how many tonnes of sodium would

be needed to produce 96 tonnes of titanium. [3] .................................................................................................................. .................................................................................................................. .................................................................................................................. (ii) Titanium forms another chloride in which 48 g of titanium is combined

with 71 g of chlorine. Calculate the simplest formula for this chloride of titanium. Show your working. [2]

Ar(CI) = 35.5 Ar(Ti) = 48

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


FORMULAE FOR SOME COMMON IONS

POSITIVE IONS NEGATIVE IONS

NAME FORMULA NAME FORMULA

Aluminium Al3+ Bromide Br-

Ammonium NH4+ Carbonate CO3

2-

Barium Ba2+ Chloride CI-

Calcium Ca2+ Fluoride F-

Copper(II) Cu2+ Hydroxide OH-

Hydrogen H+ Iodide I-

Iron(II) Fe2+ Nitrate NO3-

Iron(III) Fe3+ Oxide O2-

Lithium Li+ Sulfate SO42-

Magnesium Mg2+

Nickel Ni2+

Potassium K+

Silver Ag+

Sodium Na+


MARK SCHEMES


General Marking Instructions 1. Over-rigidity in the interpretation of the mark scheme is not intended and it is

accepted that points may be made in a variety of different ways including converse and counterpoints.

2. Phonetic spelling is allowed except where there is a possibility that scientific terms

might be confused. 3. When candidates list alternative answers to short answer questions, the general

principle to be followed is: right + wrong = no mark. In a question requiring a set number of responses, where a candidate has supplied extra responses above the required number each error/contradiction negates one correct response, however responses considered neutral (ie not incorrect) are not penalised.

4. The principle of error carried forward is generally applied where an incorrect value

calculated in one part of a question is treated as being correct for the purposes of subsequent parts.

5. When marking calculations, substitution into an incorrect equation is not credited and

hence subsequent calculations within that section will score zero. 6. Alternative answers are accepted even if not noted on the marking scheme as long

as they are appropriate, correct and valid in the context of the science. Note that in some cases specific terms are a requirement. Any uncertainty about the acceptability of an answer is clarified by consultation with the Principal Examiner or Team Leader.

7. Marking Quality of Written Communication: The marking scheme for these questions

includes indicative content which gives the outline of the content of a good answer. Candidates should generally cover most, if not quite all, of the points in the indicative content to achieve the highest mark band on these questions and if candidates present alternative valid approaches these are equally acceptable. The tests to be applied are coherence, which is expressed well scientifically, as well as completeness and correct science at an appropriate level.

8. Abbreviations used in mark schemes. / = alternatives not = unacceptable answer(s) accept = not an ideal answer but just accepted on this occasion (…..) = further material that would be required for a full answer but is not

required on this occasion


Additional Science - Chemistry 2 Marking Scheme

Foundation Tier

Question Details Marks

1. (a) (i) all bars plotted correctly (2) two bars plotted correctly (1) – tolerance ±½ small square

2

(ii) I C 1 II A 1

(iii) I same volume / amount of water in each tube

1

II same amount / mass / volume of soap same type of soap used same water temperature – any one

1

(b) (i) calcium 1

(ii) strengthens teeth / bones reduces incidence of heart disease tastes better / makes better beer limescale coating inside metal pipes stops poisonous salts dissolving in water – any one

1

Total marks for question 8 2. (a) (i) I 3 1 II 7 1

(ii) I electrons 1 II neutrons 1

(b) recognise the presence of 3 H atoms but only one N atom (1)

14 + 3 = 17 (1) (2) for correct answer only

2

Total marks for question 6



3. (a) (i) simple molecular 1

(ii) ionic 1

(b) (i) (free) electrons (1) positive (charge/terminal/end) - do not accept ‘positive ions’(1)

2

(ii) ductile / can be stretched into wires malleable / can be beaten into shape

1

(c) A – methane B – diamond C – graphite – all three correct for (2), one correct for (1)

2

Total marks for question 7 4. (i) I photochromic materials 1 II hydrogels 1

(ii) place wires in hot water / water at 50 °C or hotter (1)

nitinol wire regains original shape but steel is not affected (1)

2

Total marks for question 4 5. (i) to prevent it from reacting with oxygen in the air

1

(ii) I Hazard – burns skin on contact / reacts with moisture on skin (1) Precaution – carry out reaction behind safety screen do not accept ‘wear safety goggles’ (1)

2

II hydrogen 1

(iii) KCl (1) 2 in box before formula (1) – formula must be correct

2

Total marks for question 6 6. (a) A – lithium bromide (1)

B – sodium chloride (1) C – potassium iodide (1)

3

(b) tubes / pipettes contaminated with solution C / potassium iodide (1) ensure tubes are washed before use / clean pipette for each solution (1)

2




7. (i) I all points plotted correctly (1) – tolerance ±½ square – allow 1 error straight line of best fit attempted (1)

2

II 87 (g per 100 g water) ±1 g 1 III 48 ±1 ºC 1 IV higher the temperature, the higher the solubility (1)

solubility of potassium bromide increases gradually as the temperature rises but that of potassium nitrate increases very quickly / roughly doubles for each 20 ºC rise

– or converse explanation (1)

2

(ii) I repeat experiment to see if similar results are obtained

1

II values very close together / same values at two different temperatures if measured to the nearest 1 g per 100 g water

1




8. (a) Indicative content: A chlorine atom contains 17 positively charged protons which balance the charge associated with the electrons. The number of electrons in an atom’s outermost orbit is its group number and the number of occupied orbits is its period number – Group 7 and Period 3 in the case of chlorine. 5 – 6 marks The candidate constructs an articulate, integrated

account correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar.

3 – 4 marks The candidate constructs an account correctly

linking some relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar.

1 – 2 marks The candidate makes some relevant points, such

as those in the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar.

0 marks The candidate does not make any attempt or

give a relevant answer worthy of credit.

6

(b) atoms of the same element with different numbers of neutrons in the nucleus/atoms with the same number of protons but different numbers of neutrons accept chlorine-35 has 18 neutrons and chlorine-37 has 20 neutrons

1




9. (a) (i) 1st reading at 40 ºC

1

(ii) too slow putting connecting syringe / putting stopper on flask gas escaping acid heated to 30 (ºC) rather than 40 (ºC) / acid not heated enough larger marble chips used / marble chips had smaller surface area – any one

1

(iii) four correct means of three results i.e. 71, 48, 17 and 9 (seconds) (1) mean of two results for 40 ºC i.e. 33 (seconds) (1)

2

(b) the higher the temperature, the higher the rate of reaction / the faster the reaction / the more quickly gas is produced

1

(c) (i) sensible range e.g. 0.4 to 2.0 (M) or 1.0 to 2.0 (M) (1) at least four different concentrations, equal intervals (1)

2

(ii) more particles present in solution of higher concentration (1) second mark should only be awarded if the candidate coherently links greater collision rate to greater number of particles present collisions more likely / more collisions per second (1)

2



Additional Science - Chemistry 2 Marking Scheme

Higher Tier


1. (i) I all points plotted correctly (1) – tolerance ±½ square – allow 1 error straight line of best fit attempted (1)

2

II 87 (g per 100 g) water ±1 g 1 III 48 ±1 ºC 1 IV higher the temperature, the higher the solubility (1)

solubility of potassium bromide increases gradually as the temperature rises but that of potassium nitrate increases very quickly / roughly doubles for each 20 ºC rise

– or converse explanation (1)

2

(ii) I repeat experiment to see if similar results are obtained 1 II values very close together / same values at two different

temperatures if measured to the nearest 1 g per 100 g water

1




2. (a) Indicative content: A chlorine atom contains 17 positively charged protons which balance the charge associated with the electrons. The number of electrons in an atom’s outermost orbit is its group number and the number of occupied orbits is its period number – Group 7 and Period 3 in the case of chlorine. 5 – 6 marks The candidate constructs an articulate, integrated








6

(b) atoms of the same element with different numbers of neutrons in the nucleus/atoms with the same number of protons but different numbers of neutrons accept chlorine-35 has 18 neutrons and chlorine-37 has 20 neutrons

1




3. (a) (i) 1st reading at 40 ºC

1

(ii) too slow putting connecting syringe / putting stopper on flask gas escaping acid heated to 30 (ºC) rather than 40 (ºC)/acid not heated enough larger marble chips used/marble chips had smaller surface area – any one

1

(iii) four correct means of three results i.e. 71, 48, 17 and 9 (seconds) (1) mean of two results for 40 ºC i.e. 33 (seconds) (1)

2

(b) the higher the temperature, the higher the rate of reaction / the faster the reaction / the more quickly gas is produced

1

(c) (i) sensible range e.g. 0.4 to 2.0 (M) or 1.0 to 2.0 (M) (1) at least four different concentrations, equal intervals (1)

2

(ii) more particles present in solution of higher concentration (1) second mark should only be awarded if the candidate coherently links greater collision rate to greater number of particles present collisions more likely / more collisions per second (1)

2

Total marks for question 9 4. (a) Rf value for sample B calculated / distance travelled by

recovered ink calculated - workings must be shown (1) Specimen B has Rf value 0.7 / travelled 4.2 (cm) so is the ink that matches the sample found at the crime scene (1)

2

(b) (i) lilac accept purple 1

(ii) atomic spectroscopy

1




5. (a) (i) diagram clearly showing magnesium atom losing 2 electrons (1) diagram clearly showing oxygen atom gaining 2 electrons (1) charges on both ions shown (1)

3

(ii) strong attraction between ions of opposite charge / requires large amount of (heat) energy to break bonds

1

(b) (i) covalent 1

(ii) weak bonds between molecules 1

(c) (i) strong (covalent) bonds between all atoms / in all directions 1

(ii) weak bonds between layers allow them to slide over one another

1

Total marks for question 8 6. (a) (i) bromine is more reactive than iodine but less reactive than

chlorine

1

(ii) Br2 + 2 NaI → 2 NaBr + I2

1

(b) sodium bromide gives a cream precipitate or sodium iodide gives a yellow precipitate

1

(c) Ag+ + Cl− → AgCl

1

Total marks for question 4 7. (i) C is the hardest because its lather is the poorest /

lasts least time

1

(ii) because each sample gave similar results on repeating once

1

(iii) results confirm the conclusion because C has the poorest lather in each group (1) each group may have used different volumes of water / soap solution / concentrations of soap solution (1)

2

(iv) magnesium / Mg2+

1




8. (a) Indicative content: Crude oil is vaporised (by heating) and pumped in at the bottom of a fractionating column. The column is hottest at the bottom but even at high temperature the heavier fractions (or those with longer hydrocarbon chains) condense and can be collected. Lighter fractions (or those with shorter chains) rise through the column and cool and condense at their boiling temperatures, while the very lightest fractions are collected as gases at the top of the column. 5 – 6 marks The candidate constructs an articulate, integrated








6

(b) (i) (4 413) + 612 + (3 496) (1) 3752 (kJ) (1) (2) for correct answer only

2 (ii) −1076 (kJ) do not accept +1076 kJ

1




9. (a) (i) regain their original shape 1

(ii) (reversibly) change colour 1

(b) (i) Substitution 4(23) : 1(48) or 96/48 = 2 moles (1) Ratio 8(23) : 2(48) or 4 moles : 1 mole ∴ 8 : 2 (1) 184 (tonnes) (1) (3) for correct answer only

3

(ii) Ratio 48/48 : 71/35.5 = 1:2 (1) TiCl2 (1) no mark for formula unless working is shown

2



ASSESSMENT GRIDS


MARK SPECIFICATION GRID

Additional Science - Chemistry 2

Specimen unit examination

FOUNDATION TIER

C2 – Atoms, bonding and chemical change


AO1 AO2 AO3

Target Totals for Paper 24 24 12 60 HSW QWC

Question Number


1. (a)(i)

7. (i), (j)

2

8

1. (a)(ii) 2

1. (a)(iii) 2

1. (b) 2

2. (a)(i) 1. (b), (d), (e),

(f)

2 6

2. (a)(ii) 2

2. (b) 2

3. 3. (a), (b), (g) 7 7

4. (i) 3. (f)

2 4

4. (ii) 2

5. (i)

2. (a), (b), (d)

1 6

5. (ii) 1 2

5. (iii) 2

6. (a) 2. (f), (g)

3 5

6. (b) 2

7. (i) 7. (h)

4 2 8

7. (ii) 2

8. 1. (d), (h), (i) 7 7

9. (a)(i)(ii)

4. (a), (b)

2

9

9. (a)(iii) 2

9. (b) 1

9. (c) 4

Raw Totals: 24 25 11 60



Additional Science - Chemistry 2


HIGHER TIER C2 – Atoms, bonding and chemical change


AO1 AO2 AO3


Question Number


1. (i) 7. (h)

4 2 8

1. (ii) 2

2. 1. (d), (h), (i) 7 7

3. (a)(i)(ii)

4, (a), (b)

2

9

3. (a)(iii) 2

3. (b) 1

3. (c) 4

4. (a) 2. (f) 7. (f), (n)

2 4

4. (b)(i)(ii) 2

5. (a) 3. (c), (d), (e), (f), (g)

1 3 8

5. (b)(c) 4

6. (a)

2. (e), (g)

1 1 4

6. (b) 1

6. (c) 1

7. (i)(ii)(iii) 7. (i), (k)

3 4

7. (iv) 1

8. (a) 5. (a) 6. (e)

6 9

8. (b) 3

9. (a) 3. (k), (l) 6. (a), (c)

2 7

9. (b) 5

Raw Totals: 25 23 12 60



0

GCSE ADDITIONAL SCIENCE FOUNDATION TIER (Grades G-C) PHYSICS 2: Electricity, forces and nuclear physics SPECIMEN PAPER (1 hour)

INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces at the top of this page. Answer all questions. Write your answers in the spaces provided in this booklet. INFORMATION FOR CANDIDATES The number of marks is given in brackets at the end of each question or part-question. You are reminded that assessment will take into account the quality of written communication used in your answer to question 8(a).


Equations and Units

power = current × voltage P = IV

energy transfer = power × time E = Pt units used (kWh) = power (kW) × time (h) cost = units used × cost per unit

% efficiency = useful energy [or power] transfer 100total energy [or power] input

×

density = massvolume

mV

ρ =

wave speed = wavelength × frequency c = λf

speed = distancetime

acceleration [or deceleration] = change in velocitytime

vatΔ

=

v u at= + where

12 ( )x u v t= +

u = initial velocity v = final velocity a = acceleration t = time x = displacement

currentvoltage resistance = VR

I=

momentum = mass × velocity p= mv

resultant force = mass × acceleration F = ma

change in momentumforce = time

pFtΔ

=

work = force × distance W = Fd

primary coil voltage primary coil turnssecondary coil voltage secondary coil turns

= 2

1

2

1

NN

VV

=

pressure = forcearea

FpA

=


Units 1 kWh = 3.6 MJ T / K = θ / °C + 273 SI multipliers

Prefix Multiplier Prefix Multiplier p 10−12 k 103

n 10−9 M 106

μ 10−6 G 109

m 10−3 T 1012


Answer all questions

1. List A gives three statements about forces acting on a skydiver when falling through the air. List B gives 5 possible effects on the motion of the skydiver. Draw one line from each statement in list A to the correct effect it would have in list B. [3] List A List B

The weight and air resistance are equal.

The weight is greater than the air resistance.

The air resistance is greater than the weight.

The skydiver moves upwards.

The skydiver speeds up.

The skydiver stops.

The skydiver slows down.

The skydiver falls at constant speed.


2. Radon is a radioactive gas. It occurs naturally and rises through small cracks in the Earth's rocks. It enters buildings through the floor.

The graph below shows the Health Protection Agency's assessment of risk of a person getting lung cancer from radon gas and how it depends on the radon level in the home.

(a) Use only the information in the graph to find:

(i) the percentage risk to health from a radon level of 20 Bq per m3, ……..% [1] (ii) the radon level that gives a 2% risk of getting lung cancer........... Bq/m3 [1]

(b) The average radon level in British homes is 20 Bq/ m3. The government's Action

Level, where householders should take steps to reduce the radon in their homes, is 10 times the average level.

(i) How many Bq/m3 is the Action Level? Action level = ……….Bq/m3 [1]

(ii) What information can you get from the graph about the lung cancer risk if a

person lives in a home at the Action Level of radon? [2]

…………………………………………………………………………………………. …………………………………………………………………………………………. ………………………………………………………………………………………….

20 70 130 180 Radon level in the home (Bq/m3)

Percentage risk of getting lung cancer

3%

2%

1%

0


3. A group of car engineers tests the braking distance for a new design of car tyre at different speeds.

Their results are plotted on the grid below. (a) (i) The engineers think that their result for 15 m/s is incorrect. Look at all the points and suggest why. [2] ………………………………………………………………………………. ……………………………………………………………………………….

(ii) Estimate the correct value of the braking distance at 15 m/s and show on the graph grid how you obtained your answer. [2]

Breaking distance at 15 m/s = ……………

0 5 10 15 20 25 30 Speed (m/s)

Braking distance (m) 70

60

50

40

30

20

10

0


(iii) Suggest two things the engineers would need to do before their results are accepted by other car engineers. [2]

1. ……………………………………………………………………………

………………………………………………………………………………...

2. ……………………………………………………………………………

………………………………………………………………………………...

(b) In a second test, the engineers compared the car moving at 10 m/s with a heavier lorry also moving at 10 m/s. They both stopped in a distance of 7m. Tick ( ) three things from this list which are bigger for the lorry than the car. [3]

Its speed

Its kinetic energy

Its momentum

Its stopping time

Its braking force


4. (a) In 2003, over 3000 people were killed and 33,000 seriously injured in collisions on Britain's roads.

The chances of a pedestrian surviving a collision depends upon how fast the vehicle is travelling. This is shown on the graph.

Use the information in the graph to suggest why many people think that there should be a 20 mph speed limit outside schools instead of the present limit of 30 mph. [2]

…………………………………………………………………………………………

…………………………………………………………………………………………

…………………………………………………………………………………………

…………………………………………………………………………………………

(b) Speed cameras have been placed around Britain to encourage drivers to stay within

the speed limit. The photograph shows a car passing a camera in a 30 mph speed limit area.

10 20 30 40 50 Speed (mph)

100

80

60

40

20

0

chan

ce o

f sur

viva

l (%

)


When the camera detects a speeding car, it takes two photographs. The white road markings are painted 1.5 m apart. From the first photograph to the second the car moved forward 5 spaces.

(i) Calculate the distance travelled by the car between the two photographs. [1]

Distance = ………… m

(ii) The second photograph is taken 0.5 seconds after the first one. Calculate the speed of the car. [2]

Speed = ………… m/s


5. The following equation shows a nuclear reaction. 2 3 4 11 1 2 0H H He n+ → +

This reaction only takes place if the particles on the left hand side of the equation move very quickly towards each other. This needs a very high temperature.

(a) Underline the correct word or words in the brackets of each sentence below. [3]

(i) The particles that collide together in this reaction are nuclei of

atoms of (hydrogen, helium, oxygen).

(ii) The particle 10n that is released in the reaction is (a neutron, a nucleus,

nitrogen). (iii) This is an example of a (fission reaction, chain reaction, fusion reaction).

(b) Give two reasons why this reaction is very difficult to control. [2]

1. .…………………………………………………………………………………… ……………………………………………………………......………………………. 2. .……………………………………………………………………………………. ……………………………………………………………………………………..….

(c) Give one reason why this reaction is likely to be very important during the next

100 years. [1] ................................................................................................................................... ...................................................................................................................................


6. The graph shows the first 20 s of the motion of a van already moving at a constant speed. At 20 s the van accelerates with constant acceleration for 20 s to reach a new constant speed

of 30 m/s. The van continues at this new constant speed for a further 20 s.

(a) Complete the graph to show the motion of the van between 20 s and 60 s. [2] (b) Calculate the acceleration of the van during the period when it is accelerating. [3]

Acceleration = ……………….. m/s2

0 10 20 30 40 50 60 Time (s)

40

30

20

10

0

Speed (m/s)


7. The diagram shows the forces on a small test rocket as it takes off.

(a) Underline the phrase in the bracket which completes each of the following sentences correctly. [The rocket thrust doesn't change.] [3]

(i) As the rocket takes off, the thrust from the engines is (less than, the same as,

greater than) the weight of the rocket and fuel. (ii) As the rocket gets higher, the weight of the rocket and fuel (become less,

stays the same, becomes greater). (iii) As the rocket gets higher, the resultant force on it (becomes less, stays the

same, becomes greater). (b) The test rocket is powered by 3 engines each of which produces a thrust of 2 000 N. The mass of the rocket and its fuel is 500 kg.

(i) Use the information above to fill in the details in the following table for the

time when the engines are first fired. [3] [On the Earth a 1 kg body has a weight of 10 N].

Quantity Size

Weight of rocket & fuel …………………. N

Total thrust produced by the engines …………………. N

Resultant force on rocket …………………. N

(ii) Calculate the take-off acceleration of the rocket. [3] Acceleration = ……………….. m/s2

Total thrust from engines

Weight of rocket plus fuel


8. Nuclear medicine uses radioactive isotopes as tracers and for the treatment of cancers within the body.

A working thyroid gland rapidly gathers the element iodine from the bloodstream. Radioactive isotopes of iodine can be produced in hospitals ready for use. Radiation from radioactive iodine can be detected outside the body and can also be used to kill cancers within the thyroid gland.

The table shows four radioactive isotopes of iodine.

Isotope of Iodine

Radiation emitted Half life

Iodine-123 gamma 13.2 hours

Iodine-128 beta 25 minutes

Iodine-129 beta 16 000 000 years

Iodine-131 beta and gamma 8⋅4 days

(a) Use your knowledge of the properties of beta and gamma radiation and information

from above to discuss which of these isotopes of iodine are suitable for use as a radioactive tracer for the thyroid gland or for treating thyroid cancer. [6 QWC]

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

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

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

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

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

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

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

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

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

(b) Iodine-131 has a mass number of 131 and an atomic number of 53.

State the number of protons, neutrons and electrons in a neutral atom of Iodine-131.

Number of protons = ………..

Number of neutrons = ………..

Number of electrons = ……….. [3]


9. A student investigates how the current through a 12 V filament lamp varies with voltage between 0 and 12 V.

(a) Draw a labelled diagram of a circuit that can be used to obtain the readings. [2] (b) The student obtained the following readings of current against voltage for the lamp.

Voltage (V) Current (A)

0.0 0.0

1.0 0.5

2.0 1.0

3.4 1.5

4.5 2.0

8.1 2.5

11.8 3.0

(i) Use the grid on the next page to draw a graph of current against voltage for the lamp. The scale of the voltage axis is given for you. [3]


(ii) Another student suggested that each reading should be repeated at least twice to see how repeatable the results are.

Use the graph to discuss whether this is necessary. [2] ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ………………………………………………………………………………………

(iii) Describe carefully how the current in the lamp changes as the voltage

increases from 0 V to 11.8 V. [2] ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ………………………………………………………………………………………

0 2 4 6 8 10 12 Voltage (V)

Current (A)



0

GCSE ADDITIONAL SCIENCE HIGHER TIER (Grades D – A*) PHYSICS 2: Electricity, forces and nuclear physics SPECIMEN PAPER (1 hour)



communication used in your answers to questions 4 and 7(a).


Equations and Units

power = current × voltage P = IV

energy transfer = power × time E = Pt units used (kWh) = power (kW) × time (h) cost = units used × cost per unit

% efficiency = useful energy [or power] transfer 100total energy [or power] input

×

density = massvolume

mV

ρ =

wave speed = wavelength × frequency c = λf

speed = distancetime

acceleration [or deceleration] = change in velocitytime

vatΔ

=

v u at= + where

2 2 2v u ax= + 21

2x ut at= + 12 ( )x u v t= +

u = initial velocity v = final velocity a = acceleration t = time x = displacement

currentvoltage resistance = VR

I=

power = current2 × resistance P = I 2R

momentum = mass × velocity p = mv

resultant force = mass × acceleration F = ma

change in momentumforce = time

pFtΔ

=

work = force × distance W = Fd

kinetic energy = 2mass×speed

2 21

2KE mv=

change in potential

energy = mass × gravitational field strength × height

PE = mgh

primary coil voltage primary coil turnssecondary coil voltage secondary coil turns

= 2

1

2

1

NN

VV

=

pressure = forcearea

FpA

=

pVT

= constant

E = mc2

p = pressure V = volume T = kelvin temperature


Units 1 kWh = 3.6 MJ T / K = θ / °C + 273 SI multipliers

Prefix Multiplier Prefix Multiplier p 10−12 k 103

n 10−9 M 106

μ 10−6 G 109

m 10−3 T 1012


Answer all questions

1. During take-off, astronauts experience the largest force from the acceleration, the "g force", just before the rocket engines shut down. This question explores why. The diagram shows a small test rocket on its launch pad.

The test rocket is powered by 3 engines, each of which produces a constant thrust of 2 000 N. The mass of the rocket and its fuel is 500 kg.

(a) (i) Use the information above to fill in the details in the following table for the time when the engines are first fired. [3]

[On the Earth a 1 kg body has a weight of 10 N].

Quantity Size

Weight of rocket & fuel …………………. N

Total thrust produced by the engines …………………. N

Resultant force on rocket …………………. N

(ii) Calculate the take-off acceleration of the rocket. [3]

Acceleration = ……………… m/s2

Total thrust from engines

Weight of rocket plus fuel


(b) The rocket engines together burn up 10 kg of fuel per second. Assuming that the thrust of the engines is constant, calculate the acceleration of the rocket 10 seconds into the take-off. Show your working clearly. [3]

Acceleration = ………………. m/s2

(c) Explain clearly why astronauts experience the largest acceleration just before the engines shut down. [2]

……………………………………………………….............………………………… ……………………………………………………….............………………………… ……………………………………………………….............………………………… ……………………………………………………….............…………………………


2. A student investigates how the current through a 12 V filament lamp varies with voltage between 0 and 12 V.

(a) Draw a labelled diagram of a circuit that can be used to obtain the readings. [2]

(b) The student obtained the following readings of current against voltage for the lamp.

Voltage (V) Current (A)

0.0 0.0

1.0 0.5

2.0 1.0

3.4 1.5

4.5 2.0

8.1 2.5

11.8 3.0

(i) Use the grid on the next page to draw a graph of current against voltage for the lamp. The scale of the voltage axis is given for you. [3]


(ii) Another student suggested that each reading should be repeated at least twice more to

assess the repeatability of the results. Use the graph to discuss whether this is necessary. [2]

………………………………………………………………………………………… ………………………………………………………………………………………… …………………………………………………………………………………………

(iii) Describe carefully how the resistance of the lamp changes as the voltage increases from 0 V to 11.8 V. [2]

………………………………………………………………………………………… ………………………………………………………………………………………… …………………………………………………………………………………………

0 2 4 6 8 10 12 Voltage (V)

Current (A)


(c) The student is making a 40 W light source for a model theatre and decides to use a pair of these identical lamps in parallel, as shown below. She adjusts the power supply so that that the ammeter reads 5.0 A.

Use data from the graph to show clearly by calculation how close this arrangement is to 40 W. [3]

Total power = ………………………. W

A 5.0 A


3. The graph shows the first 20 s of the motion of a van already moving at a constant speed. At 20 s the van accelerates with constant acceleration for 20 s to reach a new constant speed

of 30 m/s. The van continues at this new constant speed for a further 20 s.

(a) Complete the graph to show the motion of the van between 20 s and 60 s. [2] (b) Calculate the acceleration of the van during the period when it is accelerating. [3]

Acceleration = ……………….. m/s2

(c) Use your graph to calculate how far the van travels when it is accelerating, i.e. between 20 and 40 seconds. Show your working clearly. [3]

Distance travelled = ……………….. m

0 10 20 30 40 50 60 Time (s)

40

30

20

10

0

Speed (m/s)


4. Nuclear medicine uses radioactive isotopes as tracers and for the treatment of cancers within the body.

A working thyroid gland rapidly gathers the element iodine from the bloodstream.

Radioactive isotopes of iodine can be produced in hospitals ready for use. Radiation from radioactive iodine can be detected outside the body and can also be used to kill cancers within the thyroid gland.

The table shows four of the isotopes of radioactive iodine.

Form of Iodine

Radiation emitted Half life

Iodine-123 gamma 13.2 hours

Iodine-128 beta 25 minutes

Iodine-129 beta 16 000 000 years

Iodine-131 beta and gamma 8⋅4 days

Use your knowledge of the properties of beta and gamma radiation and information from above to discuss which of these isotopes of iodine are suitable for use as a radioactive tracer for the thyroid gland or for treating thyroid cancer. [6 QWC]

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5. The diagram shows an uncontrolled nuclear fission reaction. When a neutron strikes an nucleus of 235

92 U , the nucleus splits, releasing two fast neutrons together with the fission fragments of barium (Ba) and krypton (Kr).

(a) Complete the nuclear equation for this reaction. [2]

235 1 9092 0 36

U n Kr + + →

(b) A nuclear reactor makes use of boron steel control rods and a graphite moderator.

Explain how the control rods and moderator are important in maintaining a safe sustainable fission reaction. [4]

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23592 U

23592 U

23592 U

10 n

neutron 10 n

krypton

barium

10 n

10 n

10 n

10 n

10 n


6. Read the following passage about carbon-14 dating.

Carbon-14 (C-14) is a β emitter. One of the problems scientists face when undertaking C-14 dating is that the sample will almost certainly have other radioactive isotopes in it, such as potassium-40. This will result in false readings. A common technique is to react the carbon from a very small sample – typically 1 milligram – to produce benzene, which is a liquid. This procedure removes the impurities. They detect the carbon-14 by counting the small flashes of light produced in the benzene by the beta decay. The process of producing the benzene introduces another impurity, radon-222, which decays by β emission with a half life of 5½ days. Because of this the scientists leave the benzene sample for several weeks before making measurements.

(a) How does leaving the benzene sample for several weeks improve the results? [2]

………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… …………………………………………………………………………………………

(b) The activity of C-14 in a 1 mg sample of modern carbon is 1200 counts per week. The

grid on the next page shows the decay curve over a period of 12500 years.

Determine the half life of C-14 and label relevant quantities on the graph. [3]

Half life = ……………….. years


(c) A group of archaeologists took a 1 mg sample of carbon from a wooden bowl. They

measured the activity over a 1 week period. Their measurement was 200 counts but they said the true activity could lie anywhere between 160 and 240 counts per week.

What could the scientists say about the age of the bowl? Use the graph and your answer to (b). Show your working clearly. [4]

…………………………………………………………………………………………

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0 5000 10000 15000 20000 25000 Time (years) 0

Decay graph for C-14 in 1 mg of carbon

Act

ivity

(cou

nts /

wee

k)

1200

1000

800

600

400

200


7. A car-safety engineer is checking the design for a crumple zone in a car. According to the computer models, the crumple zone produces a force of 480 000 N when it is being compressed in a front collision.

The car has a mass of 1200 kg, including passengers. The design requirement for the maximum crumple distance of the crumple zone is 0.6 m.

(a) The engineer uses ideas of kinetic energy and work to show that the crumple distance at 25 m/s is almost 0.8 m.

Explain clearly and use calculations to show how she could arrive at this figure. [6 QWC]

………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… (b) The figure of 0.8 m is too long, so she suggests 2 possible changes to the design of the

car:

• make the crumple zone stiffer, i.e. it exerts a bigger force; • make the car lighter.

Underline one of these suggestions and explain how it would result in a shorter stopping distance. [2]

………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… …………………………………………………………………………………………………


MARK SCHEMES


General marking instructions 1. Over-rigidity in the interpretation of the mark scheme is not intended and it is accepted that

points may be made in a variety of different ways including converse and counterpoints. 2. Phonetic spelling is accepted except where there is a possibility that scientific terms might be

confused. 3. When candidates list alternative answers to short answer questions, the general principle to be

followed is: right + wrong = no mark. In a question requiring a set number of responses, where a candidate has supplied extra responses above the required number each error/contradiction negates one correct response, however responses considered neutral are not penalised.

4. The principle of error carried forward is generally applied where an incorrect value calculated

in one part of a question is treated as being correct for the purposes of subsequent parts. 5. Marking calculations: unless the marking scheme specifies otherwise, a fully correct answer,

without working scores all the available marks. The marks for the initial steps of a calculation shown in the mark scheme are available whether or not the final solution is correct. Substitution into an incorrect equation is not credited and subsequent calculations based upon the incorrect initial step within that section will score zero. The result of the calculation may be used to obtain marks in a subsequent section on the principle of error carried forward.

6. Alternative answers are accepted even if not noted on the marking scheme as long as they are

appropriate, correct and valid in the context of the science. Note that, in many cases, specific terms are a requirement. Any uncertainty about the acceptability of an answer is clarified by consulting with a Principal Examiner or Team Leader.

7. Marking Quality of Written Communications. The marking scheme for these questions

includes indicative content. This statement gives the outline of a good answer. Candidates should generally cover most, if not quite all, of the points in the indicative content to achieve the highest mark band on these questions and if candidates present alternative valid approaches these are equally acceptable. The tests to be applied are coherence, which is expressed well scientifically, as well as completeness and correct science at an appropriate level.

8. Abbreviations used in mark schemes. / = alternatives e.c.f. = error carried forward not = unacceptable answer(s) allow = not an ideal answer but just accepted on this occasion if qual(ified) = only acceptable as (part of) an answer if additional detail is given or equiv = or equivalent point reference to... = these general ideas are required although they may be expressed

differently or made using different terminology and in a different sequence

[…..] = material in square brackets is either clarification or further material that would be required for a full answer but is not required on this occasion

b.o.d = benefit of the doubt


Additional Science - Physics 2 Marking Scheme

Foundation Tier


1 List A List B Box 1 → Box 5 (1) Box 2 → Box 2 (1) Box 3 → Box 4 (1) [− 1 per extra line, minimum 0]

3

Total marks for question 3 2 (a) (i) 0.2 % 1 (ii) 130 Bq / m3 1 (b) (i) 200 Bq / m3 1 (ii) Cannot get an accurate answer stated or implied (1)

greater than 3% stated / number about 3.5% [accept 3.1 – 4.0%] (1) 2 Total marks for question 5 3 (a) (i) Others points lie on smooth curve / curve with no (or little) scatter

(1) – this point out [or equiv] (1) [1st marking point difficult; 2nd marking point easier]

2

(ii) 16 ± 1 m/s (1) Indication on graph linked to trend of other points, e.g. by an appropriate interpolation between neighbouring points(1) [NB a straight line interpolation between the 10 and 20 m/s points will give an answer of 18.5 m – 1 mark only can be awarded for this] 2

(iii) Any 2 × (1) • Repeat all readings [to assess repeatability] • Repeat and correct [or verify]15 m/s point • Get others to repeat experiment • Other sensible suggestion 2

(b) kinetic energy (1)

momentum (1) braking force (1) [additional tick −1; all boxes ticked → 0]

3

Total marks for question 9 4. (a) Statement on increasing chance of survival at low speeds (1) [or by

impl.] backed up by survival figures at 30 mph [80%] and 20% [96 ± 2 %] (1) [Statement on the potential victims being children is neutral] 2

(b) (i) [5 × 1.5 =] 7.5 m (answer) 1

(ii) Speed = 5.05.7

(e.c.f.) (1) = 15 m/s (1) 2




5. (a) (i) hydrogen [more than one underlined → no credit] (1) (ii) a neutron [more than one underlined → no credit] (1) (iii) fusion reaction [more than one underlined → no credit] (1) 3 (b) Reference made to the high temperature [i.e. selection of this

information from the question stem] or pressure (1). Appropriate comment about the difficulty of maintaining this temperature [or high pressure] or the need for strong magnetic fields to [keep the gas away from the container walls] (1) [NB Both marks obtainable if candidate bases answer on either magnetic or inertial confinement]. 2

(c) Reference to need to generate from low carbon sources or to replace

[diminishing] fossil fuels. ["Global warming" by itself is insufficient]

1

Total marks for question 6 6. (a) Correct shape of v-t graph, i.e. sloping upwards in a straight line from

(20,20) and becoming a straight horizontal line (1) Graph becomes horizontal at (40,30) and the graph extends to (60, 30) (1) [ignore extensions beyond (60,30)] 2

(b)

Use of takentime

yin velocit changeon accelerati = [or by implication] (1)

Acceleration = 20

2030 −or

2010

(1) = 0.5 [m/s2] (1) 3

Total marks for question 5 7. (a) (i)

(ii) (iii)

greater than (1) becomes less (1) becomes greater (1) 3

(b) (i) 5000 N (1)

6000 N (1) 1000 N (ecf) (1) 3

(ii) Statement / use of Resultant forceAcceleration

mass= (1) [or by impl.]

Acceleration = 1000(e.c.f.)500

(1) = 2 [m/s2] (1) 3




8. (a) Indicative content: Beta radiation is easily absorbed in the body. It can kill cells, including cancer cells and can also induce cancers in healthy tissue. Gamma radiation penetrates tissue, so can be detected outside the body; it is much less effective at killing cells and also produces less damage to healthy ones. The isotopes used need to have a short half life to avoid long-term exposure to radiation. This is especially the case for tracers. Iodine-123 is the only one which only emits gamma radiation and it has a short half life, so it is useful as a tracer. The other three isotopes could be used in thyroid cancer treatment but iodine-129 has a very long half life [and iodine-125 has too short a half life] so that iodine-131 is the most appropriate in radiotherapy for thyroid cancer because it is a beta emitter with a short half life. [NB. No penalty for suggesting I-128 is the most appropriate for the same reason]. 5 – 6 marks The candidate constructs an articulate, integrated account


3 – 4 marks The candidate constructs an account correctly linking some relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar.

1 – 2 marks The candidate makes some relevant points, such as those in the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar.

0 marks The candidate does not make any attempt or give a relevant answer worthy of credit.

6

(b) 53 (1)

78 (1) 53 (1) 3



9. (a) Circuit with power supply and lamp and ammeter and voltmeter correctly connected Means of varying voltage / current indicated (1) 2

(b) (i) Current scale: linear + whole vertical axis used (1)

Points correctly plotted ± ½ minor division (1) Smooth curve drawn [straight line for lowest 3 readings] (1) 3

(ii) Comment that points lie v close to [on] a smooth curve (1) Suggestion that this implies repeatable results / less repeatability would probably have more scatter / other appropriate comment. (1) 2

(iii) Current increases with voltage (1) Rate of increase of current with voltage decreases with increasing voltage [however expressed but meaning must be clear] (1) [Note: 9(b)(iii) is not common to the 2 tiers – the F-tier refers to current and the H-tier equivalent refers to resistance] 2



Additional Science - Physics 2 Marking Scheme

Higher Tier


1. (a) (i) 5000 N (1) 6000 N (1) 1000 N (ecf) (1) 3

(ii) Statement or use of Resultant forceAcceleration

mass= (1)

Acceleration = 1000(e.c.f.)500

(1) = 2 m/s2 (1) 3

(b) Attempt to work out mass loss (1)

Total mass = 400 kg (1) Resultant force = 2000 N or acceleration = 5 m/s2 (1) 3

(c) One mark is awarded for a correct and relevant statement of fact,

e.g. resultant force increases with time (1)….. Second mark can only be awarded if the candidate correctly and coherently links a second fact with the observation, e.g. …and the mass decreases, so the acceleration increases [until the engines shut down] (1) 2

Total marks for question 11 2. (a) Circuit with power supply and lamp and ammeter and voltmeter

connected correctly (1) Means of varying voltage / current indicated (1) 2

(b) (i) Current scale: linear + whole vertical axis used (1)

Points correctly plotted ± ½ square (1) Smooth curve drawn [straight line for lowest 3 readings] (1) 3

(ii) Comment that points lie v close to [on] a smooth curve (1) Suggestion that this implies repeatable results / less repeatability would probably have more scatter / other appropriate comment. (1) 2

(iii) For low voltages the resistance is ~ constant (1) [for higher voltages] the resistance increases with voltage. [Note: 2(b)(iii) is not common to the two tiers – the H-tier refers to resistance and the F-tier equivalent refers to current.] 2

(c) Attempt to use 2.5 A (1)

Use of P = VI with correct voltage (1) Total power ~ 41 W (1) 3




3. (a) Correct shape of v-t graph, i.e. sloping upwards in a straight line from (20,20) and becoming a straight horizontal line (1) Graph becomes horizontal at (40,30) and the graph extends to (60, 30) (1) [ignore extensions beyond (60,30)] 2

(b)

Use of takentime

yin velocit changeon accelerati = [or by implication] (1)

Acceleration = 20

2030 − or 2010 (1) = 0.5 [m/s2] (1)

3 (c) Area under graph approach:

Clear identification of area involved, i.e. the trapezium between 20 and 40 s – in words or on graph (1) Substitution into equation for area of triangle and area of rectangle [or area of trapezium], i.e. 1

2 10 20 20 20× × + × [or 12 (20 30) 20+ × ]

(1) Distance travelled = 500 m. (1) Alternative equation of motion approach:

Identification of relevant EoM, e.g. ( )2

u vx t+= (1)

Substitution, e.g. 20 30 202

x += × (1)

Distance travelled = 500 m (1) 3 Total marks for question 8



4. (a) Indicative content: Beta radiation is easily absorbed in the body. It can kill cells, including cancer cells and can also induce cancers in healthy tissue. Gamma radiation penetrates tissue, so can be detected outside the body; it is much less effective at killing cells and also produces less damage to healthy ones. The isotopes used need to have a short half life to avoid long-term exposure to radiation. This is especially the case for tracers. Iodine-123 is the only one which only emits gamma radiation and it has a short half life, so it is useful as a tracer. The other three isotopes could be used in thyroid cancer treatment but iodine-129 has a very long half life [and iodine-125 has too short a half life] so that iodine-131 is the most appropriate in radiotherapy for thyroid cancer because it is a beta emitter with a short half life. [NB. No penalty for suggesting I-128 is the most appropriate for the same reason].

5 – 6 marks The candidate constructs an articulate, integrated account correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar.



0 marks The candidate does not make any attempt or give a relevant answer worthy of credit. 6




5. (a) 235 1 90 143 192 0 36 56 0

U n Kr + Ba 2 n⎡ ⎤⎣ ⎦+ → + 1 1

0 0or n + n⎡ ⎤⎣ ⎦

Ba and 2n [or n + n] shown (1) Values of Z and A all corrct (1) 2

(b) One mark is awarded for a correct and relevant statement of fact for each

of control rods and moderator [i.e. 2×(1)]. 2nd mark for each of control rods and moderator awarded only if the candidate correctly and coherently links a second fact [2 × (1)]. e.g. Control rods linked to absorption of excess neutrons ( ) to keep the energy output / temperature constant [however expressed as long as the purpose is clear] ( ). Moderator linked to slowing down / thermalising neutrons emitted from fission reactions ( ) [when they collide with the moderator nuclei] because slow neutrons are more efficient at initiating fission ( ). 4

Total marks for question 6 6. (a) One mark is awarded for a correct an relevant statement of fact, e.g.

[Counts from Rn-222 halve every 5½ days (1) . . . The second mark is only awarded if the candidate correctly and coherently links a second point, e.g. . . . so after a few weeks hardly any Rn-222 left [but count from C-14 unaffected] (1) 2

(b) Activity of 600 [or 300] indicated on graph (1) with the time reading

indicated (1) Half life in range 5600 – 5800 years (1) 3

(c) (i) Sensible method communicated of handling the decays beyond the

end of the graph (2), e.g. Reasonable attempt at continuing the decay curve ( ); smooth extrapolation passing through (17 100, 150) [and (22 800, 75)] e.c.f. on half life ( ) [Alternatively: Communicating of looking on the existing graph at a time of one half life before 160 ( ) and 240 ( ), i.e. 320 and 480 counts per week]. Range of ages: 13 200 ± 200 (1) to 16 600 ± 200 (1) [e.c.f. on half life]. [If one answer given based upon 200 counts [14 700 ± 200] then 2 max is awarded.] 4




7. (a) Indicative content: The equation, Kinetic energy = ½ mv 2 , is stated and used to show that the initial kinetic energy is 375 000 J*. The relationship Word done = energy transfer is stated and applied to the force exerted by the crumple zone and the energy transfer of 375 000 J (e.c.f.). The equation: Work = Force × distance is used with the force of 480 000 N and 375 000 J (e.c.f) and manipulated to show that the crumple distance is 0.78 m. [*NB 1. The initial kinetic energy does not need to be evaluated explicitly for full marks – the expression ½ × 1200 × 252 can be used throughout. NB 2. The question implies but does not explicitly require this approach, so candidates who proceed by calculating the deceleration, using F=ma and then the distance travelled, e.g. using v 2 = u 2 + 2ax, will be assessed in the same way as those applying work and energy concepts. 5 – 6 marks The candidate constructs an articulate, integrated account




0 marks The candidate does not make any attempt or give a relevant answer worthy of credit. 6

(b) One mark is awarded for a correct and relevant statement of fact .

The second mark is only awarded if the candidate correctly and coherently links a second point., eg. For crumple zone response: Work done is the same (1)…… so if F is larger d would be smaller (1) [or accept calculation of F needed for 0.6 m crumple zone] For car mass response: Less work needs to be done (1) ……..because kinetic energy is less (1) 2



ASSESSMENT GRIDS



Additional Science - Physics 2


FOUNDATION TIER

P2 – Electricity, Forces and Nuclear Physics


AO1 AO2 AO3


Question Number

Syllabus Reference

1 3(b), (d) 3 3

2. (a) 5(c), (d)

2 5

(b) 3 3. (a) HSW / 4(g) 6

9

(b) 3(b), 4(d), (g) 3 4. (a) HSW 2

5

(b) (i) 2(b)/HSW

1 (ii) 1 1

5. (a) 6(b), (e) 3 6

(b) 6(g) 2 (c) 6(f)/HSW 1 6. (a) 2(a) 2

5

(b) 2(b), (c) 1 2 7. (a)

3(d),(e) 3

9

(b) (i) 3

(ii) 1 2 8. (a) 5(e) 6

9

(b) 6(a) 3 9. (a)

1(d)/HSW 2

9

(b) (i) 3 (ii),(iii) 4 Raw Totals: 22 25 13 60



Additional Science - Physics 2


HIGHER TIER

P2 – Electricity, Forces and Nuclear Physics


AO1 AO2 AO3


Question Number

Syllabus Reference

1. (a) (i)

3(d), (e)

3

11

(ii) 1 2

(b) 1 2 (c) 2 2. (a)

1(d)/HSW 2

12

(b) (i) 3 (ii)(iii) 4 (c) 1(b), (g) 3 3. (a) 2(a) 2

8

(b) 2(b), (c)

1 2 (c) 1 2 4. (a) 5(e) 6 6

5. (a) 6(b) 2 6

(b) 6(d) 4 6. (a) 5(b)/HSW 2

9

(b) 5(b) 3

(c) 5(a)/HSW 4 7. (a)

4 (c), (e), (g) 2 4

8

(b) 2 Raw Totals: 22 26 12 60


CONTROLLED ASSESSMENTS


Candidate Name ............................................................................... Centre Name ...................................................................... Centre Number .. ...............

Declaration by candidate

I have read and understood the Notice to Candidates (GCSE and Principal Learning: Controlled Assessments). I have produced the attached work without assistance other than that which is acceptable under the scheme of assessment. Candidate's name: ........................................................................................................ Candidate's signature: ................................................... Date .................................

Declaration by teacher or lecturer

I confirm that: 1. the candidate's work was conducted under the conditions laid out by the

specification; 2. I have authenticated the candidate's work and am satisfied that, to the best of my

knowledge, the work produced is solely that of the candidate. Teacher's name: ........................................................................................................ Teacher's signature: ................................................... Date .................................

Year - SPECIMEN

Assessment area Mark Awarded

Hypothesising & Planning / 12

Collecting, reviewing & processing data / 12

Analysing & reviewing procedure / 12

Analysing data & concluding / 12

TOTAL / 48

GCSE Additional Science: Investigation Controlled Assessment


Additional Science: Controlled Assessment

Investigation into the effect of pectinase on pectin.

Pectinase is an enzyme which catalyses or speeds up the breakdown of pectin. Pectin is present in fruit such as apples and oranges. A manufacturer of packet fruit juice wants to know if he should use pectinase during the processing of juice from the fruit. PART 1 – this part is not assessed. Before you do the assessed part of this controlled assessment you will carry out preliminary work on the action of pectinase on fruit. You may do this either on your own, in small groups, as part of a whole class piece of work, or your teacher may demonstrate this to you. You should write a brief report on this investigation including:

results analysis of the results.


Investigation into the effect of pectinase on pectin.

PART 2 – this part is assessed. Now you are going to move on to the investigation which you are going to plan and carry out.

Under what conditions could pectinase be used to improve the processing of juice from the fruit?

Investigate this question and write a report of your work. You only need to investigate one factor. You should include the following steps.

You should

(a) consider the details of the question you are going to investigate – you can discuss it with other people, including others taking the assessment;

(b) research the topic, e.g. by looking for information on the internet and possibly include a pre-test;

(c) produce a hypothesis and give some background information which supports it;

(d) produce a plan for undertaking the investigation – you should use information from the work in PART 1;

(e) consider any risks associated with this investigation – you may use the Risk Assessment sheet for this.

You will do parts (c), (d) and (e) under supervision and without discussing it with anyone apart from your teacher.

You should now proceed to carry out the investigation and write it up. You will be able to co-operate with other people in obtaining data but the report must be your own work.

While carrying out your investigation, you should review your method and change it if necessary in the light of experience.

Report Your report should include:

a suitable presentation of all your results

evaluations of the results and discussion of your findings

conclusions and review of the hypothesis

evaluation of the investigation.


GC

SE A

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Teacher Guidance Notes This controlled assessment task is in the context of sections 1(f) and 5(d) of the Biology 2 content . The task, including the preliminary work, is structured as follows: 1. Preliminary work: Section 5(d) of the specification of Biology 2 should be carried out

as the preliminary work. This may be by individual or group work by the candidates or by teacher demonstration. This is not assessed, but the experience of the preliminary work and the results obtained will be used to inform their planning for the remaining part of the controlled assessment.

2. Collection of secondary data: As part of the planning process, the candidates need to

collect secondary data. These data can be used by the candidates in two ways: to inform themselves about the repeatability and reproducibility of the data which could inform their decision about the number of repeats; to provide some evidence which may be of use in their hypothesising. The secondary data may also be useful in their analysis / evaluation. The results of other candidates in the preliminary work could be used and supervisors could provide a data set for the candidates to search. It is important that the candidates select appropriate data for themselves. Centres having difficulty in obtaining appropriate data which may be used should contact WJEC.

3. Research: This stage of the controlled assessment is carried out under a limited

level of control. Candidates may carry out some work in conditions not under the supervision of the teacher. The candidates should be given the opportunity to do some research which can involve internet searches and text books into enzyme action / fruit juice yield. Supervisors may prepare materials for candidates to use in this research phase. Copies of these materials should be included with the candidates’ work.

4. Planning an investigation: This stage of the controlled assessment is carried out

under a high level of control, i.e. the candidates work individually. The candidates use the results of their research and their preliminary work to plan an investigation into fruit juice yield and pectinase. They should: • Identify the variables which they intend to investigate • Identify variables which need to be controlled • Suggest a relationship between the dependent and independent variables • Give reasons for suggesting this relationship – coming from their research and /

or their scientific knowledge • Give details of their planned procedure – drawing on their experience of the

preliminary work, including the repeatability of the data achieved in it • Include a risk assessment.

Note that the plan need not be complete at this stage – it can be modified in the light of experience, e.g. in the light of experience of the repeat results. It is not anticipated that the plans occupy more than 2 or 3 sides of A4. This stage of the controlled assessment may take up to 2 hours of formally-supervised time.

5. Data acquisition: This stage of the controlled assessment is carried out under a

limited level of control; candidates with similar plans are allowed to work in groups. Credit is available in the next phase of the controlled assessment for reporting decisions made during data acquisition, e.g. modifying the method of fixing the controlled variables or checking suspect results. It is anticipated that this stage of the controlled assessment will take up to approximately 2 hours. During this stage, feedback should be limited to clarification of the requirements of the assessment.


6. Report writing: This stage of the controlled assessment is carried out under a high level of control, i.e. the candidates work individually. The candidates present their data appropriately, e.g. using tables, charts and graphs, chosen to allow the hypothesis to be tested as rigorously as possible. Any decisions made during data acquisition, including modifications to the plan should be presented with justification. The report should include suitable analysis of the data and a conclusion relating to the hypothesis. The extent and quality of the data should be explored alongside a discussion on the degree of confidence in the conclusion.

It is anticipated that this stage of the controlled assessment will take 1 - 2 hours and that the extent of the report, including tables and graphs, should occupy not more than 4 sides of A4. During this stage, feedback should be limited to clarification of the requirements of the assessment.

7. Assessment: This stage of the controlled assessment is carried out under a medium

level of control. Supervisors use the WJEC marking criteria to assess the report using a “best fit” approach.


Controlled Assessment

Additional Science: Investigation

Marking Criteria 1. The work of each candidate should be assessed in each of the following fields

1. Hypothesising and planning 2. Collecting, reviewing and processing data 3. Analysing and reviewing procedure 4. Analysing data and concluding

2. The maximum mark in each assessment field is 12 and is subdivided into the

following bands: 0 marks, 1 – 3 marks, 4 – 6 marks, 7 – 9 marks, 10 – 12 marks 3. The bands are hierarchical; however, a “best fit” approach should be adopted, i.e.

minor shortcomings at one level can be overcome by a candidate clearly meeting the additional demands of a higher level.

4. The demands of quality of written communication are incorporated into the criteria in

fields 2 and 4. 5. Centres are required to annotate work to show which level is achieved in each field

and to indicate the evidence for the achievement of the level and position within the level.

6. The marks for each of the fields should be entered into the table on the controlled

assessment cover sheet and the authenticating declarations by the candidate and teacher / lecturer signed and dated.

7. A single mark out of 48 is submitted.


Hypothesising and planning

Mark range Description Exemplification – indicative assessment points

0 No evidence of planning is presented.

1-3

Candidates work from a given hypothesis and make a plan to collect some relevant data without necessarily controlling variables. They take some account of safety in their plan.

Possible hypothesis, e.g. as enzyme concentration/ temperature increases, the runniness of pectin increases, the candidates plan to do some or all of:

• time how long pectin takes to run through a burette • repeat a reading at least once • work safely, e.g. mention a normal laboratory rule

4-6

Candidates make a simple hypothesis relating the independent and dependent variables. Plan identifies independent and dependent variables without necessarily identifying controlled variables explicitly. They identify any significant hazards relating to the investigation.

Candidates make a simple qualitative hypothesis, e.g. as enzyme concentration / temperature increases, the time taken decreases, but candidates may use other independent variables. They may identify the enzyme concentration and the time to run through the burette as the dependent and independent variables and give a significant hazard e.g. allergy to enzyme or potential injury from breaking burette

7-9

Candidates make a hypothesis relating the variables to be investigated and discuss it in terms of scientific knowledge or the results of their preliminary research. Plan identifies the variables which need to be controlled and includes ranges and intervals of variables and appropriate numbers of repeats. They use the experience of previous work to produce a simple risk assessment for the investigation.

In addition to the above candidates • relate the hypothesis qualitatively to concepts of effects of enzyme activity or justify

it in terms of experience of the preliminary work or research, including secondary data

• identify explicitly all significant variables including the variables which need to be controlled [concentration/volume of enzyme/substrate, temperature if appropriate, pH]

• plan a range and intervals of the independent variable which should lead to a test of the hypothesis [at least 5 different and reasonably spaced values]

• plan to take at least three readings at each value of the independent variable – or justify why fewer are sufficient, e.g. from the preliminary work

• produce a simple risk assessment for the investigation


Hypothesising and planning Mark range Description Exemplification – indicative assessment points

10-12

Candidates additionally use the results of scientific knowledge, preliminary work and research to justify the hypothesis. They explain how they control variables and justify the need to control specific variables in terms of a valid investigation (or discuss the limitations of the investigation where variables cannot be controlled). They discuss and use the results of preliminary work to inform details of the plan, e.g. in terms of ranges and number of repeats and any relevant safety issues.

In addition to the above, candidates • use detailed scientific knowledge such as collision theory or properties of pectin to

justify hypothesis • use their scientific knowledge of experimental techniques and enzymes to explain why

named variables need to be controlled and how e.g. by using buffers to control pH or as appropriate

• use the details of the preliminary work, including secondary data, to justify the number of repeats readings required [in terms of the expected scatter of the individual readings]


Collecting, reviewing and processing data Mark range Description Exemplification – indicative assessment points

0 No evidence of collected data presented.

1-3

Candidates work safely, they collect some data relevant to the investigation and display the collected data.

Working with due regard for safety, candidates • make a single relevant measurement of the dependent variable for one value of the

independent variable • measure the dependent variable for at least two different values of the independent

variable, without necessarily controlling other variables • present the measured values of dependent and independent variables – not

necessarily in systematic form or with correct use of units

4-6

Candidates collect sufficient relevant data which enables an initial assessment of the validity of the hypothesis to inform the plan. They select simple forms and styles of presentation of the data including a simple table, graph, chart or diagram which enables data to be interpreted and they process some data mathematically e.g. by averaging.

In addition to the above, candidates • make measurements of the dependent variable for at least 3 values of the

independent variable • repeat a measurement of the dependent variable for at least one value of the

independent variable • make enough measurements of the dependent variable to enable an initial

judgement the validity of the hypothesis • produce a table of results for at least 3 values of the independent variable, not

necessarily including repeated readings of the dependent variable for all values of the independent variable or produce a graph of the dependent against the independent variable, which may show lack of precision e.g. of plotting, axis labels

• determine the mean value of the dependent variable, for at least 3 values of the independent variable



7-9

Candidates collect sufficient valid data which enables them to make a judgement on a simple hypothesis and review details of the plan in the light of results. Using standard forms and styles of presentation appropriate to the task, they display data systematically, including detailed graph or chart; they use judgement in the selection and mathematical processing of data which they display appropriately.

Candidates • collect data from at least 5 widely spread values of the independent variable

sufficient to allow a judgement on a qualitative hypothesis and comment on any changes to the details of the plan, e.g. number of repeats, in the light of experience

• display data, with units, in appropriate sequence and suitable arrangement in a table or tables with headings which may have omissions e.g. units

• produce a graph of the dependent against the independent variable with good choice of scales and labelled axes but may have plotting errors or incomplete axis labels

• average, ignoring suspect values if appropriate, and correct use of significant figures

10-12

Candidates collect sufficient high-quality valid data which enables them to make a good judgement of a detailed hypothesis and they discuss the sufficiency of the data, reflecting upon the plan. They select and effectively use high level forms and styles of presentation appropriate to the task; they process data appropriately and accurately producing a high-level display of the data.

Candidates • produce data that are sufficient [in terms of spread of independent variable values

and variability of dependent variable values] to test a hypothesis and consider the sufficiency of the data

• produce a clear table or tables of results and appropriately manipulated values with clear, accurate headings and appropriate units

• produce a graph, with linear scales and complete axis labels, which can be used to test hypothesis, e.g. enzyme concentration (%) vs time taken for mixture to run through burette (sec) with appropriate and accurate joining of plots


Analysing and reviewing procedure Mark range Description Exemplification – indicative assessment points

0 No evidence of analysis or review presented.

1-3

Candidates make simple relevant comments about techniques in the procedure and on the quality of the evidence produced. They make a simple statement referring to other data, e.g. in the preliminary work or research.

• make a simple statement about how the procedure was carried out, such as the difficulty of timing, e.g. it was difficult to time it

• make a simple, non-factual statement about how accurate they think the data are • brief, non-qualified statement

4-6

Candidates make detailed relevant comments about techniques in the procedure and use the spread/trend of their raw data to comment on the repeatability of the data produced. They make a detailed statement referring to other data, e.g. in the preliminary work or research.

• more detailed statement e.g. it was difficult to time it accurately • make a statement which refers to how spread out the data were, either the plotted mean

points or the individual readings for a particular value of the dependent variable • comment on how close different groups’ results were in the preliminary work or how the

relationship fits in with their research

7-9

Candidates suggest changes to the techniques in the procedure. They justify improvements in terms of the repeatability of the measurements or justify an assertion that no improvement is necessary. They comment on other data, e.g. in the preliminary work or research.

• suggest a way of improving the evidence or show why the evidence does not need improvement, e.g. use different type of water bath, thermostatic rather than using a bunsen.

• relevant comment e.g. referring to temperature variation during the experiment. • comment on how this investigation supports or contradicts the research

10-12

Candidates discuss the limitations of the investigation. They relate the outcome of the investigation with information discovered in the candidate’s research, making a detailed comparison.

• suitable comment e.g. it was difficult to ensure consistency when timing • examine the repeatability and/or reproducibility [from the preliminary work] and discuss

to what extent the data support the conclusion • consider whether a different conclusion is also supported by the data • discuss in detail to what extent the data are in line with the initial research


Analysing data and concluding


0 No analysis or conclusion presented.

1-3

Candidates make a simple, relevant statement about the data possibly identifying some trends or patterns in the data. The presentation may have major inaccuracies of spelling punctuation and grammar; little use of scientific vocabulary.

• make a correct statement referring to the data which may be about one value of the dependent variable • make a correct statement, referring to at least two values of the dependent variable, referring to a trend • uses non-scientific terminology, incomplete sentences and in a way which requires the assessor to search

for relevant points

4-6

Candidates give a detailed, accurate description of the trends or patterns in the data, relating the trends to information discovered in the candidate’s research. The presentation has inaccuracies in spelling, punctuation and grammar; use of scientific vocabulary is limited.

• make a simple statement linking the variation of the dependent variable with that of the independent variable

• comment on how the trend compares with that expected • some use of basic scientific terms, sentences may not be accurately constructed with incorrect spelling

7-9

Candidates identify the relationship(s) between variables revealed in the data, relating this to the hypothesis. They make a comparison of the outcome of the investigation with information discovered in the candidate’s research. The presentation has no major inaccuracies in spelling, punctuation and grammar; use of scientific vocabulary is good.

• make a qualitative but detailed statement linking the variables • comment on the extent to which the relationship supports the hypothesis • comment on how this investigation supports or contradicts the research • mainly appropriate use of scientific terms, simple sentences with no major inaccuracies in construction

and spelling

10-12

Candidates produce a valid conclusion from the data collected. They discuss the extent to which the data support the hypothesis (including whether an alternative hypothesis is supported) and discuss the extent to which more/improved quality of the data would improve their confidence in the conclusion. The presentation has good spelling, punctuation and grammar; use of scientific vocabulary is appropriate and of a high standard.

• make a conclusion relating the independent and dependent variable, or show that the expected relationship is not supported by the data

• examine the repeatability and/or reproducibility [from the preliminary work] and discuss to what extent the data support the conclusion

• consider whether a different conclusion is also supported by the data, e.g. discuss in detail to what extent the data are in line with the initial research

• uses scientific terms appropriately throughout, clear well expressed sentences with correct spelling

GCSE in ADDITIONAL SCIENCE - Specimen Assessment Materials 166


GCSE Additional Science


Assessment Objective Total

AO1 AO2 AO3 HSW QWC

As percentage of the Controlled Assessment 18.75% 25.0% 56.25% 100%

Marks for the Controlled Assessment 9 12 27 48


Candidate Name ............................................................................... Centre Name ...................................................................... Centre Number ..................




I confirm that: 1. the candidate's work was conducted under the conditions laid out by the specification; 2. I have authenticated the candidate's work and am satisfied that, to the best of my knowledge, the work produced is solely that of the candidate. Teacher's name: ........................................................................................................ Teacher's signature: ................................................... Date .................................

Year - SPECIMEN


Hypothesising & planning / 12




TOTAL / 48




Investigating hand warmers

Using an exothermic reaction Many people who enjoy outdoor activities such as fishing, hill-walking or skiing may have used ‘hand warmers’ during particularly cold weather. There are different types available to buy but they all make use of an exothermic reaction which releases heat when two chemicals react inside them. Your task is to discover exactly what should be included in your hand warmer in order to ensure that the greatest amount of heat is produced. PART 1 – this part is not assessed Before you do the assessed part of this controlled assessment you will carry out preliminary work on exothermic and endothermic reactions. You may do this either on your own, in small groups, as part of a whole class piece of work or your teacher may demonstrate this to you. You should write a brief report on this preliminary work including:

results analysis of the results


Investigating hand warmers

PART 2 – this part is assessed Now you are going to move on to the investigation which you are going to plan and carry out. What you should include in your hand warmer to produce the greatest amount of heat. Investigate this question and write a report of your work. You should include the following steps:

You should

(a) consider the details of the question you are going to investigate – you can discuss it with other people, including others taking the assessment,

(b) research the topic, e.g. by looking for information on the internet, (c) produce a hypothesis and give some background information which

supports it, (d) produce a plan for undertaking the investigation – you should use

information from the work in PART 1, (e) consider any risks associated with this investigation – you may use the

Risk Assessment sheet for this.

You will do parts (c), (d) and (e) under supervision and without discussing it with anyone apart from your teacher.

You should now proceed to carry out the investigation and write it up. You will be able to co-operate with other people in obtaining data but the report must be your own work.

During the carrying out of your investigation you should review your method and change it if necessary in the light of experience.

Report Your report should include:

a suitable presentation of all your results evaluations of the results and a discussion of your findings conclusions and a review of the hypothesis evaluation of the investigation


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Teacher Guidance Notes This controlled assessment task is in the context of section 6 of the Chemistry 2 content, in particular section 6(e). The task, including the preliminary work is structured as follows: 1. Preliminary work: The candidates should undertake some experimental work looking

at substances [compounds and elements] which react, to determine whether the reactions are endothermic or exothermic and to measure temperature changes. The following substances are offered as possibilities but others are possible:

Solutions Solids

copper sulfate ammonium chloride

sulfuric acid copper oxide

water magnesium

sodium hydrogencarbonate

zinc The brief write-up that the candidates produce is not for assessment but to give them

access to the results for planning their investigation. 2. Collection of secondary data: As part of the planning process, the candidates need to

collect secondary data. These data can be used by the candidates in two ways: to inform themselves about the repeatability and reproducibility of the data which could inform their decision about the number of repeats; to provide some evidence which may be of use in their hypothesising. The secondary data may also be useful in their analysis / evaluation. The results of other candidates in the preliminary work could be used and supervisors could provide a data set for the candidates to search. It is important that the candidates select appropriate data for themselves. Centres having difficulty in obtaining appropriate data which may be used should contact WJEC.

3. Research: This stage of the controlled assessment is carried out under a limited

level of control. Candidates may carry out some work in conditions not under the supervision of the teacher. The candidates should be given the opportunity to do some research which can involve internet searches and text books into the factors which affect the magnitude of the energy release. Supervisors may prepare materials for candidates to use in this research phase. Copies of these materials should be included with the candidates’ work.

4. Planning an investigation: This stage of the controlled assessment is carried out

under a high level of control, i.e. the candidates work individually. The candidates use the results of their research and their preliminary work to plan an investigation into one of the factors which may affect the temperature rise in a reaction mixture. They should: Identify the variables which they intend to investigate; Identify variables which need to be controlled Suggest a relationship between the dependent and independent variables Give reasons for suggesting this relationship – coming from their research and /

or their scientific knowledge


Give details of their planned procedure – drawing on their experience of the preliminary work, including the repeatability of the data achieved in it

Include a risk assessment Note that the plan need not be complete at this stage – it can be modified in the light

of experience, e.g. in the light of experience of the repeat results. It is not anticipated that the plans occupy more than 2 or 3 sides of A4. This stage of the controlled assessment may take up to 2 hours of formally assessed time.

5. Data acquisition: This stage of the controlled assessment is carried out under a

limited level of control, in that candidates with similar plans are allowed to work in groups. Credit is available in the next phase of the controlled assessment for reporting decisions made during data acquisition, e.g. modifying the method of fixing the controlled variables or checking suspect results. It is anticipated that this stage of the controlled assessment will take up to approximately 2 hours. During this stage, feedback should be limited to clarification of the requirements of the assessment.

6. Report writing: This stage of the controlled assessment is carried out under a high

level of control, i.e. the candidates work individually. The candidates present their data appropriately, e.g. using tables, charts and graphs, chosen to allow the hypothesis to be tested as rigorously as possible. Any decisions made during data acquisition, including modifications to the plan should be presented with justification. The report should include suitable analysis of the data and a conclusion relating to the hypothesis. The extent and quality of the data should be explored alongside a discussion on the degree of confidence in the conclusion.

It is anticipated that this stage of the controlled assessment may take up to 3 hours of

formally supervised time. The extent of the report, including tables and graphs, should occupy not more than 4 sides of A4. The report submitted should include the candidate's hypothesis, plan and risk assessment.

During this stage, feedback should be limited to clarification of the requirements of

the assessment. 7. Assessment: This stage of the controlled assessment is carried out under a medium

level of control. Supervisors use the WJEC marking criteria to assess the report using a “best fit” approach.







following bands: 0 marks, 1 – 3 marks, 4 – 6 marks, 7 – 9 marks, 10 – 12 marks 3. The bands are hierarchical, however, a “best fit” approach should be adopted, i.e.


4. The demands of Quality of Written Communication are incorporated into the criteria

in fields 2 and 4. 5. Centres are required to annotate work to show which level is achieved in each field









1-3


• use a simple, given hypothesis, e.g. zinc and copper sulfate cause a greater temperature rise than zinc and sulfuric acid, to plan some measurements

• plan to o measure a temperature rise o repeat a reading at least once

• consider the need to work safely, e.g. mention a normal laboratory rule

4-6


• make a simple qualitative hypothesis e.g. the more magnesium that is added, the greater the temperature rise of the sulfuric acid

• identify mass of magnesium and the temperature rise as the independent and dependent variables, possibly without stating that volume of acid must be kept constant

• describe a significant hazard e.g. sulfuric acid is corrosive/irritant

7-9


• relate the hypothesis qualitatively to concept of energy and bond breaking/making • identify explicitly all significant variables including the variables which need to be

controlled e.g. mass of solids, concentration and volume of solutions • plan a range and intervals of the independent variable which should lead to a test of

the hypothesis [at least 5 different and reasonably spaced values] • plan to take at least three readings at each value of the independent variable – or

justify why fewer are sufficient, e.g. from the preliminary work • produce a simple risk assessment for the investigation



10-12

Candidates additionally use the results of scientific knowledge, preliminary work and research to justify the hypothesis. They explain how they control variables and justify the need to control specific variables in terms of a valid investigation (or discuss the limitations of the investigation where variables cannot be controlled). They discuss and use the results of preliminary work to inform details of the plan, e.g. in terms of ranges and number of repeats and any relevant safety issues.

• use detailed scientific knowledge e.g. the relative amounts of energy required to break bonds/released by forming bonds during reactions, to justify hypothesis

• use their knowledge and understanding of the scientific techniques and chemical reactions and collision theory to explain why variables e.g. acid concentration needs to be controlled in order to carry out a valid investigation

• use the results of preliminary work, including secondary data, to justify the number of repeat readings required [in terms of the expected scatter of the individual readings]



0 No evidence of collected data presented.

1-3

Candidates work safely, they collect some data relevant to the investigation and display the collected data.

• measure a single temperature rise e.g. when sodium hydrogencarbonate is added to sulfuric acid

• measure the temperature rise for at least two different values of the independent variable, without necessarily controlling other variables

• present the measured values of temperature rise and independent variables – not necessarily in systematic form or with correct use of units

4-6

Candidates collect sufficient relevant data which enable an initial assessment of the validity of the hypothesis to inform the plan. They select simple forms and styles of presentation of the data including a simple table, graph, chart or diagram which enables data to be interpreted and they process some data mathematically e.g. by averaging.

• measure the temperature rise for at least 3 values of the independent variable e.g. volume of sulfuric acid

• repeat a measurement of the temperature rise for at least one value of the independent variable

• make enough measurements of the temperature rise to enable an initial judgement on the validity of the hypothesis

• produce a table of results for at least 3 values of the independent variable e.g. volume of sulfuric acid, not necessarily including repeat readings of temperature rise for all volumes, or produce a graph of temperature rise against volume, possibly lacking precision e.g. when plotting, labelling axes

• determine the mean value of temperature rise for at least 3 different volumes



7-9

Candidates collect sufficient valid data which enable them to make a judgement on a simple hypothesis and review details of the plan in the light of results. Using standard forms and styles of presentation appropriate to the task, they display data systematically, including detailed graph or chart; they use judgement in the selection and mathematical processing of data which they display appropriately.

• collect data from at least 5 well spread values of the independent variable, e.g. concentration of copper(II) sulfate solution, and use it to make a judgement on a qualitative hypothesis

• describe any changes made to the details of the plan in light of experience e.g. number of repeat readings

• display data in appropriate sequence in well-organised tables with headings and units, possibly with minor omissions e.g. units missing in one column

• produce a graph, e.g. of temperature rise against concentration of copper(II) sulfate solution, with good choice of scales and labelled axes (including units), possibly with one minor plotting error or incomplete axis label

• ignore suspect values when calculating means • use a sensible approach to significant figures

10-12

Candidates collect sufficient high-quality valid data which enable them to make a good judgement of a detailed hypothesis and they discuss the sufficiency of the data, reflecting upon the plan. They select and effectively use high level forms and styles of presentation appropriate to the task; they process data appropriately and accurately producing a high-level display of the data.

• produce data that are sufficient [e.g. in terms of spread of concentration of sulfuric acid solution values and variability of temperature rise values] to test their hypothesis and consider the sufficiency of the data

• display data in well-designed tables with accurate headings and appropriate units in all cases

• produce a graph with accurate scales, labelling and plotting in all cases, drawing a line of best fit, where appropriate, which can be used to test hypothesis



0 No evidence of analysis or review presented.

1-3

Candidates make simple relevant comments about techniques in the procedure and on the quality of the evidence produced. They make a simple statement referring to other data, e.g. in the preliminary work or research.

• make a simple statement about the process of carrying out their investigation e.g. it was difficult to measure the correct amount of zinc for each reaction

• make a simple, possibly incorrect, statement about how accurate they think the data are, without any reasoning

• state how data compares with preliminary work e.g. temperature rise was the same as it was during preliminary work

4-6

Candidates make detailed relevant comments about techniques in the procedure and use the spread/trend of their raw data to comment on the repeatability of the data produced. They make a detailed statement referring to other data, e.g. in the preliminary work or research.

• expand on a simple statement, possibly by adding some explanation e.g. difficult to know exactly how much more powder is needed to get to the next required amount

• make a statement which refers to how spread out the individual readings for a particular value of the temperature rise were

• comment on how results compare with those from preliminary work (possibly including other groups’ data) or how the observed relationship, e.g. change in temperature rise with change in copper(II) sulfate solution concentration, fits in with their research

7-9


• suggest a way of improving the evidence, e.g. by measuring solution volumes more accurately using a burette, or justify why the evidence does not need improvement

• explain how a change to method will improve quality of data collected, e.g. measured temperature rises will be closer to the true value if solution volumes are more accurately measured

• comment on how results of this investigation support or contradict preliminary work or research



10-12

Candidates discuss the limitations of the investigation. They relate the outcome of the investigation with information discovered in the candidate’s research, making a detailed comparison.

• suggest possible reasons why measured values may not be very close to true values, e.g. heat lost from container as reaction occurs so maximum recorded temperature will always be lower than true value

• examine repeatability and/or reproducibility [data from preliminary work] • discuss to what extent the data support the conclusion • consider whether a different conclusion is also supported by the data • discuss in detail to what extent the data are in line with the initial research


Analysing data and concluding Mark range Description Exemplification – indicative assessment points

0 No analysis or conclusion presented.

1-3

Candidates make a simple, relevant statement about the data possibly identifying some trends or patterns in the data. The presentation may have major inaccuracies of spelling punctuation and grammar; little use of scientific vocabulary.

• make a correct statement about the data, possibly about only one value of the temperature rise

• make a correct statement, referring to at least two values of the temperature rise and suggesting a trend

• use non-scientific vocabulary, write incomplete sentences and use a style which requires the assessor to search for relevant points

4-6

Candidates give a detailed, accurate description of the trends or patterns in the data, relating the trends to information discovered in the candidate’s research. The presentation has inaccuracies in spelling punctuation and grammar; use of scientific vocabulary is limited.

• make a simple statement linking the variation of the temperature rise to that of the independent variable e.g. the mass of magnesium added to sulfuric acid

• comment on how the trend compares with that expected following preliminary work or research

• attempt to construct full sentences and use basic scientific vocabulary but incorrectly spell a significant proportion of key words

7-9

Candidates identify the relationship(s) between variables revealed in the data, relating this to the hypothesis. They make a comparison of the outcome of the investigation with information discovered in the candidate’s research. The presentation has no major inaccuracies in spelling punctuation and grammar; use of scientific vocabulary is good.

• make a qualitative statement linking the variables e.g. the greater the mass of magnesium added to sulfuric acid, the greater the temperature rise

• state that the relationship is broadly in line with the hypothesis, or otherwise, as appropriate

• explain how their results support or contradict their research • use scientific terms appropriately and construct simple sentences, with generally

good spelling, to effectively convey meaning



10-12

Candidates produce a valid conclusion from the data collected. They discuss the extent to which the data support the hypothesis (including whether an alternative hypothesis is supported) and discuss the extent to which more/improved quality of the data would improve their confidence in the conclusion. The presentation has good spelling punctuation and grammar; use of scientific vocabulary is appropriate and of a high standard.

• draw a conclusion relating, for example, the mass of magnesium and the temperature rise, or show that the expected relationship is not supported by the data

• examine repeatability and/or reproducibility [data from preliminary work] • discuss to what extent the data support the conclusion e.g. referring to the

maximum amount of magnesium that can be added before sulfuric acid is used up • discuss in detail to what extent the data are in line with the initial research • correctly use a range of scientific terms and express themselves with clarity and

with very few spelling errors






AO1 AO2 AO3 HSW QWC

As percentage of the Controlled Assessment 18.75% 25% 56.25% 100%

Marks for the Controlled Assessment 9 12 27 48


Candidate Name ............................................................................... Centre Name ...................................................................... Centre Number .. ...............




I confirm that: 1. the candidate's work was conducted under the conditions laid out by the

specification; 2. I have authenticated the candidate's work and am satisfied that, to the best of my

knowledge, the work produced is solely that of the candidate. Teacher's name: ........................................................................................................ Teacher's signature: ................................................... Date .................................

Year - SPECIMEN


Hypothesising & planning / 12




TOTAL / 48




Investigating terminal velocity

When objects (including people) fall through the air, they accelerate until they reach a maximum speed – known as the terminal velocity. For a human being falling without a parachute this can be more than 100 m/s. On the other hand people claim that a mouse dropped on to a flat surface will never reach a high enough speed for the impact to be fatal.

There are all sorts of factors we can investigate, e.g.

How does the size of an object affect its terminal velocity? How does the mass of an object affect its terminal velocity? How far does an object fall before it reaches terminal velocity?

You'll be able to think of several more possibilities.

PART 1 – this part is not assessed

Before you do the assessed part of this controlled assessment you will consider the third bullet point – how far does an object fall before it reaches terminal velocity. Rather than drop a man or a mouse, you will use more easily replaced objects and ones which are easier to handle, such as paper or aluminium cake cases. There are also fewer ethical issues with this approach!

Your teacher will introduce the investigation and divide up the measurements among different people.

When you have taken the measurements, you should produce a brief report containing:

your results and those of other people an analysis of your results.


Investigating terminal velocity

PART 2 – this part is assessed Now you are going to move on to investigate another question about terminal velocity. It could be one of the first 2 bullet points in PART 1 or a different question. You should (a) decide what question you are going to investigate – you can discuss this with other

people, including others taking the assessment, (b) research the topic, e.g. by looking for information on the internet, (c) produce a hypothesis and give some background information which supports it, (d) produce a plan for undertaking the investigation – you should use information from the

work in PART 1, (e) consider any risks associated with this investigation – you may use the Risk

Assessment sheet for this. You will do parts (c), (d) and (e) under supervision and without discussing it with anyone apart from your teacher. You should now proceed to carry out the investigation and write it up. You will be able to co-operate with other people in obtaining data but the report must be your own work. When carrying out your investigation, you should review your method and change it if necessary in the light of experience. Report Your report should include:

your hypothesis, plan and risk assessment • a suitable presentation of all your results evaluations of the results and discussion of your findings conclusions and review of the hypothesis an evaluation of the investigation.


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Teacher Guidance Notes This controlled assessment task is in the context of sections 3 and 4 of the Physics 2 content, especially section 3(e). The task, including the preliminary work, is structured as follows: 1. Preliminary work. The candidates collectively investigate how far an object falls

before reaching terminal velocity. This is not assessed, but the experience of the preliminary work and the results they obtain will be used to inform their planning for the remaining part of the controlled assessment.

A possible approach to this preliminary work is to time light objects, e.g. cake cases,

as they fall from a series of different heights and to plot a graph of drop height against time – the distance fallen before terminal velocity is reached can be read off the graph.

The work can be split up, some groups of candidates investigating a different mass of object, e.g. using, say, 3 nested cases. Candidates can be given the opportunity to exchange results so that the repeatability and reproducibility of the measurements can be investigated. During this preliminary part of the controlled assessment, candidates may seek and be given detailed advice.

2. Collection of secondary data. As part of the planning process, the candidates

need to collect secondary data. These data can be used by the candidates in two ways: to inform themselves about the repeatability and reproducibility of the data which could inform their decision about the number of repeats; to provide some evidence which may be of use in their hypothesising. The secondary data may also be useful in their analysis / evaluation. The results of other candidates in the preliminary work could be used and supervisors could provide a data set for the candidates to search. It is important that the candidates select appropriate data for themselves. Centres having difficulty in obtaining appropriate data which may be used should contact WJEC.

3. Research. This stage of the controlled assessment is carried out under a limited

level of control. Candidates may carry out some work in conditions not under the supervision of the teacher. The candidates should be given the opportunity to do some research which can involve internet searches and text books into the factors which affect the magnitude of the terminal velocity. They should be encouraged to relate this to the work they have done on air resistance and weight and resultant forces. Supervisors may prepare materials for candidates to use in this research phase. Copies of these materials should be included with the candidates' work. Entering the phrase terminal velocity into a search engine produces a plethora of websites, several of which are very useful and at an accessible level.

height


4. Planning an investigation. This stage of the controlled assessment is carried out under a high level of control, i.e. the candidates work individually. The candidates use the results of their research and their preliminary work to plan an investigation into one of the factors which may affect the terminal velocity of a falling object. They should • Identify the variables which they intend to investigate • Identify variables which need to be controlled • Suggest a relationship between the dependent and independent variables • Give reasons for suggesting this relationship – coming from their research and /

or their scientific knowledge • Give details of their planned procedure – drawing on their experience of the

preliminary work, including the repeatability of the data achieved in it • Include a risk assessment.

Note that the plan need not be complete at this stage – it can be modified in the light

of experience, e.g. in the light of experience of the repeat results. It is not anticipated that the plans occupy more than 2 or 3 sides of A4. This stage of the controlled assessment may take up to 2 hours of formally supervised time.

5. Data acquisition. This stage of the controlled assessment is carried out under a

limited level of control; candidates with similar plans are allowed to work in groups. Credit is available in the next phase of the controlled assessment for reporting decisions made during data acquisition, e.g. modifying the method of fixing the controlled variables or checking suspect results. It is anticipated that this stage of the controlled assessment will take up to approximately 2 hours. During this stage, feedback should be limited to clarification of the requirements of the assessment.

6. Report writing. This stage of the controlled assessment is carried out under a high

level of control, i.e. the candidates work individually. The candidates present their data appropriately, e.g. using tables, charts and graphs, chosen to allow the hypothesis to be tested as rigorously as possible. Any decisions made during data acquisition, including modifications to the plan should be presented with justification. The report should include suitable analysis of the data and a conclusion relating to the hypothesis. The extent and quality of the data should be explored alongside a discussion on the degree of confidence in the conclusion.

This stage of the controlled assessment may take up to 3 hours. The extent of the

report, including tables and graphs, should occupy not more than 4 sides of A4. During this stage, feedback should be limited to clarification of the requirements of

the assessment. 7. Assessment. This stage of the controlled assessment is carried out under a

medium level of control. Supervisors use the WJEC marking criteria to assess the report using a "best fit" approach.







following bands: 0 marks, 1 – 3 marks, 4 – 6 marks, 7 – 9 marks, 10 – 12 marks 3. The bands are hierarchical; however, a "best fit" approach should be adopted, i.e.


4. The demands of quality of written communication are incorporated into the criteria in

fields 2 and 4. 5. Centres are required to annotate work to show which level is achieved in each field









1-3


Working perhaps from a given simple hypothesis, e.g. heavier objects take a shorter time to reach the floor, the candidates plan to do some or all of: • time an object (e.g. 1 or more cake cases) to fall from a height to the floor • time a heavier object to fall from a height (not necessarily the same height) to the

floor • repeat a reading at least once • work safely, e.g. mention a normal laboratory rule

4-6


Candidates make a simple qualitative hypothesis, e.g. the heavier the object the faster it falls or the heavier the object the shorter the time it takes to reach the ground. The following points for credit relate to these hypotheses but candidates may use other independent variables e.g. surface area [size] of object Candidates • identify by implication the mass / weight of an object and the time to reach the ground

/ [terminal] speed of falling as the variables to investigate • plan to measure descent from the same height if hypothesis expressed in terms of

time or to allow object to reach terminal velocity • plan to make timings for different masses • plan to repeat timings at least once • identify a hazard or make a case that there are no significant hazards



7-9


In addition to the above, candidates • identify explicitly all significant variables, mass of object, size / area of object, shape of

object, terminal velocity [NB the hypothesis should be framed in terms of the terminal velocity and not the time to reach the ground]

• identify clearly the variables which need to be controlled [size / area and shape for the above hypothesis and drop height if time, rather than terminal velocity is the dependent variable]

• relate the hypothesis qualitatively to concepts of drag / air resistance, weight and resultant force or justify it in terms of experience of the preliminary work or research, including secondary data

• plan a range and intervals of the independent variable which should lead to a test of the hypothesis [maximum value at least 4 times the minimum value and at least 5 different and reasonably spaced values]

• plan to allow the falling object to reach terminal velocity before making measurements • plan to take at least three readings at each value of the independent variable – or

justify why fewer are sufficient, e.g. from the preliminary work • produce a simple risk assessment for the investigation

10-12

Candidates additionally justify the need to control specific variables in terms of a valid investigation or discuss the limitations of the investigation where variables cannot be controlled. They use the results of scientific knowledge, preliminary work and research to make a hypothesis. They use the results of preliminary work to inform details of the plan, e.g. in terms of ranges and number of repeats.

In addition to the above, candidates • use their scientific knowledge of forces and motion to explain why named variables

need to be controlled • use the results of research to make a quantitative hypothesis, e.g. within the model

that drag is given by kAv2, predict the relationship between terminal velocity and mass or area

• indicate how they will test the hypothesis, i.e. what graph they will plot and how they will judge to what extent the hypothesis is supported by the data

• use the details of the preliminary work, including secondary data, to justify the number of repeat readings required [in terms of the expected scatter of the individual readings] and the distance required to reach terminal velocity



0 No evidence of data collection is presented.

1-3

Candidates work safely, collect data relevant to the investigation and display collected data.

Working with due regard for safety, candidates • make a single relevant measurement of the dependent variable for one value of the

independent variable • measure the dependent variable for at least two different values of the independent

variable, without necessarily controlling other variables • present the measured values of dependent and independent variables – not

necessarily in systematic form or with correct use of units

4-6

Candidates collect sufficient relevant data which enables an initial assessment of the validity of the hypothesis to inform the plan. They select simple forms and styles of presentation of the data including a simple table, graph, chart or diagram which enables data to be interpreted; they process some data mathematically, e.g. by averaging.

In addition to the above, candidates • make measurements of the dependent variable for at least 3 widely spread values of

the independent variable • repeat a measurement of the dependent variable for at least one value of the

independent variable • make enough measurements of the dependent variable to enable the supervisor to

make an initial judgement of the validity of the hypothesis • determine the mean value of the dependent variable, which could be the time of

descent rather than terminal velocity, for at least 3 values of the independent variable • produce a table of results for at least 3 values of the independent variable, not

necessarily including repeated readings of the dependent variable for all values of the independent variable

• produce of graph of the dependent against the independent variable, which could be time of descent rather than terminal velocity



7-9

Candidates collect sufficient valid data which enables them to make a judgement on a simple hypothesis and review details of the plan in the light of results. Using standard forms and styles of presentation appropriate to the task, they display data systematically, including detailed graph or chart; they use judgement in the selection and mathematical processing of data which they display appropriately.

Candidates • control all relevant variables and ensure that terminal velocity is achieved • they determine the terminal velocity from their time measurement • collect data from at least 5 widely spread values of the independent variable

sufficient to allow a judgement on a qualitative hypothesis, which should be in terms of terminal velocity

• display data, with units, in appropriate sequence in a table or tables • average, ignoring suspect values if appropriate • produce of graph of the terminal velocity against the independent variable with

good choice of scales and well labelled axes • comment on any changes to the details of the plan, e.g. number of repeats, in the

light of experience

10-12

Candidates collect sufficient high-quality valid data which enables them to make a good judgement of a detailed hypothesis and they discuss the sufficiency of the data, reflecting upon the plan. They select and effectively use high level forms and styles of presentation appropriate to the task; they process data appropriately and accurately producing a high-level display of the data.

Candidates • produce data that are sufficient [in terms of spread of independent variable values

and variability of dependent variable values] to test a quantitative hypothesis • produce a clear table or tables of results and appropriately manipulated values,

e.g. values of v2 or √m , with appropriate units • produce a graph, with good choice of scales and clearly labelled axes, which can

be used to test quantitative hypothesis, e.g. v2 against m • consider the sufficiency of the data



0 No evidence of analysis or reviewing presented.

1-3

Candidates make simple comments about techniques in the procedure and on the quality of the evidence produced. They make a simple statement referring to other data, e.g. in the preliminary work or research.

To be awarded credit, candidates, • make a low level statement about how the procedure was carried out, e.g. the

difficulty of timing, e.g. it was difficult to time it accurately • make a low level statement about how accurate they think the data are • statements are brief and non-qualified

4-6

Candidates make detailed, relevant comments about techniques in the procedure and use the spread/trend of their raw data to comment on the repeatability of the data produced. They make a detailed statement referring to other data, e.g. in the preliminary work or research.

Candidates • make more detailed statements, e.g. it was difficult to time it accurately because the

cake cases fell so fast • make a statement referring to control variables • make a statement which refers to how spread out the data were, either the plotted

mean points or the individual readings for a particular value of the dependent variable • comment on how close different groups' results were in the preliminary work or how

the relationship fits in with their research

7-9


Candidates • suggest a way of improving the evidence or show why the evidence does not need

improvement, e.g. using light gates [to improve accuracy] or the pattern in the graph is clear and all the points lie on a smooth line [more evidence not needed]

• make a statement indicating the extent to which it was possible to control variables, e.g. the surface area of the cake cases was controlled well but sometimes there were air draughts which could have affected the results

• comment on how this investigation supports or contradicts the preliminary work and / or the research, referring to the results of different groups



10-12

Candidates discuss the limitations of the investigation. They relate the outcome of the investigation with information discovered in the candidate's research, making a detailed comparison.

Candidates, additionally, • examine the repeatability and/or reproducibility [from the preliminary work] and

discuss to what extent the data support the conclusion • justify in detail the control of variables, e.g. the confidence that terminal velocity had

been reached, or the difficulty of doing this. • discuss in detail to what extent the data are in line with the initial research



0 No relevant analysis or conclusion presented.

1-3

Candidates make a simple, relevant statement about the data, possibly identifying some trends or patterns in the data. The presentation may have major inaccuracies of spelling, punctuation and grammar; little use of scientific vocabulary

To be awarded credit, candidates, • may analyse data and review using unscientific terms, lack of units, in incomplete

sentences and in a way which requires the assessor to search for relevant points • make a correct statement referring to the data which may be about one value of the

dependent variable, e.g. one cake case took *** seconds to fall • make a correct statement referring to at least two values of the dependent variable

without necessarily referring to a trend

4-6

Candidates give a detailed, accurate description of the trends or patterns in the data relating the trends to information discovered in the candidate's research. The presentation has inaccuracies in spelling, punctuation and grammar; use of scientific vocabulary is limited.

Candidates • analyse data and review using basic scientific terms, express quantities with their

units and write in simple sentences which may not be accurately constructed • make a simple statement linking the variation of the dependent variable varies with

that of the independent variable, e.g. the greater the mass [or the greater the number of cake cases] the higher the terminal velocity [or the quicker (sic) it falls]



7-9

Candidates identify the relationship(s) between variables revealed in the data, relating this to the hypothesis. They make a comparison of the outcome of the investigation with information discovered in the candidate's research. The presentation has no major inaccuracies in spelling, punctuation and grammar; use of scientific vocabulary is good.

Candidates • analyse data and review using basic scientific terms, express quantities with their

units and write in simple sentences with no major inaccuracies in construction • make a qualitative but detailed statement linking the variables, e.g. the heavier the

object, the greater the terminal velocity , but the velocity is not proportional to the mass – as the mass increases the increase in velocity becomes less

• comment on the extent to which the relationship supports the hypothesis • comment on how this investigation supports or contradicts the research

10-12

Candidates produce a valid conclusion from the data collected. They discuss the extent to which the data support the hypothesis (including whether an alternative hypothesis is supported). They discuss the extent to which more/improved quality of the data would improve their confidence in the conclusion. The presentation has good spelling, punctuation and grammar; use of scientific vocabulary is appropriate and of a high standard.

Candidates, additionally, • analyse data and review in scientific terms, express quantities with their units and

write accurately in clear sentences • make a quantitative conclusion relating the independent and dependent variable, or

show that the expected quantitative relationship is not supported by the data, e.g. I expected the terminal velocity to be proportional to the square root of the mass but it wasn't because…..

• consider whether a different conclusion is also supported by the data, e.g. it looks as though the terminal velocity is proportional to the square root of the mass but the scatter of the points means that the terminal velocity and mass might be proportional [with backing up]

• discuss in detail to what extent the data are in line with the initial research





Assessment Objective

Total Mark

AO1 AO2 AO3 HSW QWC

As percentage of the controlled assessment 18.75% 25% 56.25% 100%

Marks for the controlled assessment 9 12 27 48

WJEC GCSE in Additional Science SAMs - 2011/ED 15/02/2011

GCSE in ADDITIONAL SCIENCE - Ysgol John Bright · 2014. 7. 28. · GCSE in ADDITIONAL SCIENCE...

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Transcript of GCSE in ADDITIONAL SCIENCE - Ysgol John Bright · 2014. 7. 28. · GCSE in ADDITIONAL SCIENCE...