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NCEA ANALYSIS for Teaching and Learning

Cheryl Harvey - Secondary Literacy and Te Kotahitanga Facilitator

Jennifer Glenn - Secondary Facilitator – Specialist Classroom Teachers

Cheryl Harvey and Jennifer Glenn, TEAM Solutions, 2007 1

CHEMISTRY

NCEA ANALYSIS for Teaching and Learning

INTRODUCTIONThis resource has been developed to support secondary schools and teachers as they consider NCEA evidence and implications for their classroom practice. It provides a model for looking at the data through a different lens. The material in the resource comes from an analysis of examiners’ reports, moderators’ reports and explanatory notes of the Achievement Standards for 2004 and 2005. This model can be updated and adapted according to the needs of an individual school or department.

Reports have been completed for the following subjects:English Science Technology Media Studies Biology Physical EducationVisual Arts Chemistry Classical Studies French Physics DramaMusic Accounting Geography History Economics MathematicsHome Economics Graphics

FRAMEWORKS FOR ANALYSISThe reports have been analysed according to:

1. Literacy and Language:comments from the reports are categorised according to : Surface features – such as neatness, layout, spelling Vocabulary Writing Reading Information skillsThis analysis is divided into NCEA Levels 1, 2 and 3.


2. Thinking:comments linked to thinking from the reports are allocated to one of the 6 levels of Bloom taxonomy. This was chosen as it links most directly to the language of NCEA. Comments from the reports are categorised according to: Remember Understand Apply Analyse Evaluate CreateThis analysis is divided into NCEA Levels 1, 2 and 3.

3. Extension features - towards Merit and Excellence:Specific comments are included which describe what students have done which lifts their responses into either Merit or Excellence at all three levels.

4. Main reasons for Failure:Specific comments are included which describe the reasons for student failure at all three levels.

5. Specific Directives to Teachers: Often in the reports, there are direct suggestions made to teachers about what is needed to improve the learning and the subsequent student outcome.

6. Vocabulary:The report includes key vocabulary , encountered either in the assessment reports, or in the explanatory notes which accompany the standard. The words are simply listed for teachers in that curriculum area to note and to use. Reference back to the Assessment Reports and the Achievement Standards would give the context and further detail. One result of this analysis has been an awareness of the amount of vocabulary a student will have to master across a range of subjects in a given year.


USING THE ANALYSIS

There are many ways using the resource to inform teaching and learning. It is possible to cut – and paste – the material in a range of ways. For example:

to link to a school goal or initiative – eg a target group such as Level 1 Literacy can be cut across all curriculum areas to look at both curriculum specific and generic learning needed for success

a particular aspect of Literacy can be cut through all levels to note the development and progression – eg Information Skills in the development of a cross-curricular research process where skills are built from Year 9

where a school seeks to raise the numbers of students gaining Literacy and Numeracy, or gaining NCEA Level 1, the Reasons for Failure category can help departments set goals for improvement

a department seeking to lift the numbers of students reaching Merit and Excellence across the board may look to the Extension Features for Merit and Excellence for guidance

where a particular standard has been identified as a target in a curriculum area, the combination of general comments and Specific Directives may be used to develop goals

If you are using this resource please acknowledge our work. We would like to acknowledge the literacy template that originally came from work done at Thames High School and which we further developed and used to produce this resource.

Cheryl HarveyJennifer GlennTeam SolutionsUniversity of Auckland.


SUBJECT: CHEMISTRY

Language and Literacy

Surface Features Vocabulary Reading Writing Information Skills

LEVEL ONE

Inaccuracies reducing at merit and excellence

Use upper and lower case letters and subscripts within formula correctly

Correct notation in formulae

Show logical progression in workings

Know symbols for common elements

Use key/appropriate terms correctly within sentences

Avoid confusion- e.g. sublimation/reverse sublimation; soluble/insoluble

Know difference - observation and inference

Use technical language with confidence and accuracy

Iupac nomenclature

Know what standards require

Interpret correctly what to do from the key words

Write/describe in detail Well set out, correct

answers Use correct notation Logical sequence of

ideas Include diagrams or

balanced equations in explanation

Clear, concise, accurate answers to discuss and explain questions

Avoid txting or other inappropriate abbreviations

Avoid repetition Give relevant fact or

description before attempt to explain

Give answers in sentences as opposed to one-word answers

Write a report – mostly in own words state references or examples

Identify correctly Predict Calculate Classify Identify from example Determine from given

material [apply] Use/draw diagrams to

explain – e.g. Lewis Describe by using

information from a diagram – role of legumes in nitrogen cycle

Identify/distinguish observation from deduction

Use knowledge in context Plan an investigation Collect data Interpret and report State references or

sources


This material is summarised from the Assessment Reports, Moderation Reports and Explanatory Notes to be found on the NZQA website. There is far more detail included in that material.


LEVEL TWO

Use correct subscripts and superscripts in equilibrium expressions

Use square brackets appropriately

Knowledge and understanding of chemical terminology

Know key aspects from explanatory notes

Ability to use scientific language and symbols appropriately and correctly – e.g. in observations

Use general terms instead of specific – e.g. ‘charged particles’, omitting reference to actual particles in the substance

Use appropriate phrases other than learned ones to show understanding e.g. ‘like dissolves like’

Iupac nomenclature Differentiate between

terms – e.g. reactants and products

Read question accurately - e.g. explaining the effect of a decrease in temperature, discussing the effect of increasing the temperature

Can interpret information provided in the question

Read a burette Add diagrams for clarity

Use full sentences, not bullet points, for discussion and explanation-type questions

Explain clearly in discussion answers

Use diagrams to add clarity to explanations -e.g. dissolving an ionic solid in water

Structure discussion answers in a logical sequence, linking ideas

Write clearly without contradiction

Organise and structure answers well

Describe clearly

Apply knowledge and skills to less familiar examples or context

Apply knowledge logically and coherently

Classify – using information

Distinguish between Determine change from

data – enthalpy Use information supplied Use diagrams for clarity Record data in a way that

can easily be interpreted



LEVEL THREE

Use appropriate number of significant figures in calculations

Set out calculations clearly

Use scientific terms – e.g. effective nuclear charge, solubility, hydrogen bonding, in their answers and then complete answers in a way that shows understanding of these terms

Use appropriate terms to present ideas

When asked to ‘explain’ a term or concept, avoid using exactly the same words/terms as in the question

Accurate use of terms - Recall, describe and use

clear definitions – e.g. hydrogen bonding and bond enthalpy; shielding and effective nuclear charge

Know the difference between key terms: clear and colourless; inter- and intramolecular

Read question accurately - e.g. explaining the effect of a decrease in temperature, discussing the effect of increasing the temperature

Can interpret information provided in the question

Read a burette Add diagrams for clarity

Use full sentences, not bullet points, for discussion and explanation-type questions

Explain clearly in discussion answers

Use diagrams to add clarity to explanations - e.g. dissolving an ionic solid in water

Structure discussion answers in a logical sequence, linking ideas

Write clearly without contradiction

Organise and structure answers well

Describe clearly

Apply knowledge and skills to less familiar examples or context

Apply knowledge logically and coherently

Classify – using information

Distinguish between Determine change from

data – enthalpy Use information supplied Use diagrams for clarity Record data in a way that

can easily be interpreted


DEEPER FEATURES – THINKING SKILLS

Remember Understand Apply Analyse Evaluate Create

LEVEL ONE

Identify correctly - e.g. reactions; bonding; colours

Symbol [beryllium]; the allotropes of carbon; origin of carbon dioxide in soft drinks

Recall basic facts– e.g. properties; chemical formulae;

Draw and name – e.g. organic molecules using appropriate iupac nomenclature

Know and define terms – e.g. polymer

Recognise difference – e.g. atomic mass/number

Classify – e.g. reactions Explain what - e.g. type

of reaction Demonstrate

understanding – e.g. particle theory, nitrogen cycle

Identify relationship – e.g. electron configuration of an atom related to chemical reactivity

Identify from examples Describe – e.g. bonding;

polymer formation Describe difference –

e.g. atoms, molecules, ions; soluble/insoluble

Describe what – e.g. role of legumes in nitrogen cycle

Identify - acid rain chemicals and reactions without confusing with other environmental pollution such as ozone layer destruction

Use knowledge in different contexts to describe

Use the information provided

Calculate and use units and round numbers appropriately and accurately

Draw accurate diagrams – e.g. lewis structures

Use the periodic table Read a burette Write accurate and

specific observations for experiments, rather than inference

Choice of relevant observation to a reaction – rote-learned observations not so

Identify observations made from chemical reactions

Explain why – e.g. observation

Ability to relate a chemical observation to a chemical equation

Explain effect – collisions between particles

Explain how – reaction described could produce solution … ; organic molecules bond; bromine distinguished between alkanes and alkenes

Demonstrate knowledge of cause and effect – acid rain

Interpret – e.g. shape of a graph; data; information about reactions

Link or refer – e.g. atomic structure and bonding to selected properties

Discuss – e.g. effect e.g. acid and base on metals and indicators

Justify the reason for an answer

Come to a valid conclusion based on data and related to purpose

Predict – e.g. products of reactions


DEEPER FEATURES – THINKING SKILLSRemember Understand Apply Analyse Evaluate Create

LEVEL ONE

Recognise symbols – first 20 elements on periodic table

Link – e.g. properties to uses; knowledge to contexts in paper; link knowledge to requirements in question

Determine from e.g. – subatomic particles in an atom/ion given mass number, atomic symbol, periodic table

Explain difference – e.g. in reactivity

Differentiate between – e.g. lab and industrial processes – ammonia preparation

Identify and distinguish observation from deduction – e.g. chemical reactions

Use knowledge in a diagram – e.g. nitrogen cycle

Apply understanding – e.g. properties hypochlorite ion; reductants

Apply knowledge in a new context – e.g. sulphite ion/preservation

Write and use equations Plan an investigation and

collect data

Interpret results and report




LEVEL TWO

Know key aspects from explanatory notes

Draw – structural formulae; lewis structures

Name using iupac conventions – organic compounds

Carry out simple calculations – ph

Know and use key terms accurately

Determine oxidation numbers

Identify – species reduced or oxidised; shapes of molecules

Complete simple half equations

Select a good model to explain – properties of metals

Identify and describe aspects of chemistry – e.g. particles in different solids, forces between them and strength

Distinguish between – alkenes and alkanes; compounds; an alcohol and carboxylic acid

Demonstrate understanding – e.g. of reactions; ph [detail], principles of electrolysis

Understand significance – magnitude of kc

Describe – e.g. structures; experimental observations for a reaction

Know relationship – e.g. hydrogen ion and ph

Link answers to principles involved

Have carried out practical work and have knowledge of observations occurring during reactions and how these observations may be used to identify substances, if required

Link knowledge to associated observations

Apply knowledge and skills to less familiar examples or contexts

Classify types – of solids using physical properties; alcohols;

Classify using information provided - reactions as exothermic or endothermic

Understand requirements – for conductivity, and link to ionic and metallic substances

Draw/interpret – e.g. lewis structures; structural formulae

Identify effect – e.g. which reactions occur at each electrode during electrolysis

Describe a trend Link with evidence

– e.g. shape of a molecule, existence of polar bonds to polarity of polar bonds

Classify – e.g. alcohols, reactions

Make comparisons

Justify why identified species in oxidation-reduction reactions

Support conclusions made with specific evidence

Describe observations and link to all species in a reaction – generalise




LEVEL TWO Apply knowledge logically and coherently

Identify the product - of addition reaction of alkenes

Can follow a multi-step reaction scheme and correctly complete missing compounds

Calculate correctly – e.g. changes/enthalpy

Apply principles/ knowledge to discuss effects, identify processes and/or relate observations – equilibrium; oxidation-reduction; electrolysis

Apply principles in different contexts - thermochemical

Use theory – e.g. collision theory

Discuss how –e.g. catalyst and decrease of temperature affect the rate of a reaction; conjugate base of a weak acid reacts with water to form a basic solution … ref. to pH and with a relevant equation




LEVEL TWO Can link and use – e.g. ph of acid solutions to hydronium concentration to discuss strength of acids

Describe and link – observations to species in a reaction

Solve problems – e.g. volumetric anbalysiis

LEVEL THREE

Write equations Recognise – e.g.

relevant reactants and products; electron configuration; bond breaking

Show understanding of chemical terms and principles – e.g. in expressions;

Describe– e.g. processes : oxidation; characteristics : electrochemical cells; properties; structures : organic products; common tests for aldehydes; aqueous systems, changing solubility, action of a buffer

Apply definitions or principles to specific question

Key ability to link - e.g. macroscopic observations to the species involved

Write balanced equations - e.g. for reactions

Ability to analyse and interpret information provided

Explain and apply principles relating to atomic, molecular, ionic properties

Use standard reduction potentials to predict the spontaneity of a reaction

Appropriately analyse and interpret information

Integrate ideas




LEVEL THREE

Recall –common observations for reactions occurring; trends – in atomic size and ionisation energy, as well as relative values of electro-negativity of p and cl; principles of optical and geometric isomers but without linking them to the formulae given

Recall and describe terms and principles

Differentiate between terms e.g. oxidant and reductant; orbitals and energy levels

Distinguish between – e.g. oxidation and reduction reactions; phosphrus-32 and element phosphorus; clear and colourless; intermolecular and intramolecular bonds; weak and strong acids and bases; solubility as concentration of a species saturated solution and any solution

Demonstrate understanding – that one half reaction must gain electrons while the other must lose electrons; that increase in radius means increase in size

Select a valid expression; appropriate expression

Find information Recognise – e.g.

functional groups

Link - e.g. observations with species involved in a reaction; ionisation energy with electrostatic attraction between nucleus and the valence electrons; intermolecular (rather than intramolecular) and melting points; concept of partial dissociation to the effect on ph

Use information – e.g. changes in oxidation numbers to identify – oxidant and reductant in a reaction; bond enthalpies or heats of formation to determine enthalpy change

Relate – e.g. observations in chemical reactions to the species involved; melting point to intermolecular forces

Use structural rather than molecular formulae

Describe and use thermochemical principles – by recalling definitions

Analyse and interpret information, and then apply the principles of organic chemistry

Use equilibrium principles to apply and/or to analyse information about aqueous systems

Identify trends Make comparisons

– e.g. between reactions

Select – e.g. a relevant indicator

Appropriately consider electro-negativity and effect of repulsion

Interpret information from chemical equations

Ability to use equilibrium principles to interpret information about aqueous systems

Write a discussion with evidence of critical thinking




LEVEL THREE

Calculate - in Lewis diagrams – valence electrons; using half-life of an isotope; involving change in mass and atomic number in a decay equation; conversion between mass and moles of a substance; to determine the enthalpy change; changes; ph, solubility

Write equations with appropriate use of equilibrium signs and arrows

Write correct formulae for common substances

Apply mathematical skill with correct order of operations, brackets etc. – e.g. to balance equations, substitute appropriate data and solve expressions

Sketch a titration curve using key points given

Know how to use calculator

Accurately use diagrams, calculations, formulae and simple written descriptions to describe

Develop a plan Describe method –

including control of variables, collection of samples and how experiments are carried out

Process data collected Present a report Make a summary Use a sample to show

process Keep a log book


EXTENSION FEATURES – TOWARDS MERIT and EXCELLENCE

Level 1 Level 2 Level 3 Was accurate Wrote complete and detailed answers Used logical sequence of ideas Showed depth of chemical knowledge and

understanding Included diagrams or balanced equations

where appropriate in explanations and discussions

Made a valid conclusion from data and linked it to purpose

Related chemical observation to chemical equation

Could explain why observation occurred Set out correct answers in complex

calculations (mass-mass) and in determining formula of a substance

Used labelled diagrams to help explain Wrote concisely and clearly without repetition Gave relevant fact or description before

attempting explanation Gave complete and detailed answers Sequenced of ideas logically Linked knowledge to question context Recalled detail – e.g. iron (ii) salt formed when

iron reacts with sulphuric acid Wrote and balance equations for reactions Demonstrated understanding – particle theory Explained - e.g. effect – particle collision Was good at answering the question that was

asked rather than the one they wanted to be asked

Understood importance

Showed depth of knowledge and understanding

Applied knowledge in less familiar contexts Discussed chemical properties clearly and fully Used terminology correctly Interpreted and used the information provided Structured and organised answers logically

and coherently, linking ideas Drew lewis structures Made links - e.g. Lewis structures to shapes

and polarities of molecules Had accurate knowledge and could use it to

discuss – e.g. electro-negativity, dipole Gave clear explanations (using terms) in

discussion answers Used diagrams to add clarity - e.g. dissolving

an ionic solid in water

Was confident in all three dimensions – macroscopic, sub-microscopic, symbolic

Demonstrated depth of knowledge and understanding

Applied terms, definitions and/or principles to the specific question

Wrote fluently, clearly and concisely Integrated formulae and equations into

discussions without being directed to do so Set out calculations in a logical, stepwise

sequence Integrated ideas Identified trends Had a clear understanding of analytical

technique Discussed with evidence of critical analysis Reached a valid conclusion – or discussed

why not Showed understanding - of the nature of

electrochemical cells using species Could analyse and interpret information

provided Could link – e.g. reduction potentials to the

relative strength of oxidants and to the spontaneous nature of oxidants

Could use changes in oxidation numbers to identify the oxidant and reductant in a reaction

Related observations in chemical reactions to the species involved

Wrote relevant, balanced equations



Level 1 Level 2 Level 3 Clearly differentiated – atoms, molecules, ions Explained links in detail – e.g. to link the

electron arrangements of atom to their chemical reactivity, and describe neon as unreactive and sodium as very/highly reactive, rather than just make a comparison of the reactivity of the two – e.g. that sodium is more reactive than neon

Could draw diagrams – Lewis Related – e.g. type of bonding present to its

likelihood to sublime Made clear distinctions – e.g. between inter-

and intramolecular bonding Could write and use balanced chemical

equations Completed detailed answers Applied knowledge to a new context – e.g.

reducing properties of sulphite ion in food preservation

Applied understanding – e.g. properties of hypochlorite ion; reductants

Demonstrated knowledge of cause and effect – e.g. acid rain

Linked knowledge to requirements of question Used technical language with confidence and

accuracy

Had a good understanding of reasons for – existence of cis-trans isomers in alkenes; reactions

Followed and completed multi-step reaction schemes

Demonstrated sound knowledge e.g. reactions of organic compounds and could link observations

Ideas correctly linked together Used data – e.g. enthalpy changes Used sign and unit correctly Applied principles to discuss effects of

changes and relate observations to those changes

Used theory – e.g. collision Discussed or showed an understanding of how

– e.g. a catalyst and decrease of temperature affect the rate of a reaction; the conjugate base of a weak acid reacts with water to form a basic solution, with ref. to ph and a written equation

Carried out calculations accurately Used appropriate chemical language Could justify why Described observations and linked to all

species in a reaction – generalised Wrote equations – half and overall

Explained and applied principles relating to atomic, molecular, ionic properties

Appropriately analysed and interpreted information provided

Demonstrated sound understanding of link between the numbers of electron shells in an atom or ion and its atomic radius and ionisation energy

Appropriately considered electro-negativity and the effect of repulsion

Correctly identified products of reactions and linked these to observations made

Identified products of organic reactions as well as the reagents needed to bring about the change

Could discuss – e.g. hydrolysis of peptides; formation of polymers

Could draw 3-dimensional structures for enantiomers with the structural features identified in the question

Made comparisons Applied principles in different contexts -

thermochemical Fluently discussed how – e.g. strength of

intermolecular forces Used correct mathematical procedures to

solve problems Could manipulate numbers/negative numbers Showed understanding – e.g. of units Interpreted information from chemical

equations Used units appropriately and accurately



Level 1 Level 2 Level 3 Completed multi-step calculations, setting out

all steps to demonstrate a clear understanding of processes and principles

Used equilibrium principles to apply and/or to analyse and interpret information – about aqueous systems

Used relevant chemical equations to support descriptive answers

Wrote equilibrium equations with correct signs and arrows

Understood difference – e.g. weak and strong acids and bases

Could link – e.g. concept of partial dissociation to the effect on ph

Understood terms – e.g. ‘solubility’ Selected the appropriate expression in which

to substitute data and then successfully manipulated the equation to solve for the unknown, make valid

Could solve expressions


MAIN REASONS FOR FAILURE

LEVEL 1 LEVEL 2 LEVEL 3


Did not choose a relevant observation to a reaction

Rote-learned observations/answers Wrote poor explanations Repeated the same observation with different

wording or repeat information to fill up space Used txt or unexplained abbreviations Did not ensure adequate working Couldn’t identify basic symbols – e.g. pb given

for iron Describe observations incorrectly, used

guesses Couldn’t write or complete equations –

word/balanced Couldn’t classify reactions Lacked knowledge so unable to describe – e.g.

oxidation-reduction reaction in terms of electron transfer; precipitation reaction in terms of formation of an insoluble substance

90640 metals, acids, bases Inability to recall basic facts – properties of

metals, colours of universal indicator in common solutions

Inability to use correct terminology e.g. ‘uncorrosive’ instead of resistant too corrosion

Inability to link – properties to uses Inability to recall or work out chemical formulae

– acids, or general equations Inability to correctly identify symbols of

elements [i ir pb = iron?] Inability to use correct notation in formulae –

upper/lowercase letters and subscripts; left charges in

Inappropriate use of rote-learned material

Lacked ability to draw and use lewis diagrams Did not use terms effectively – e.g. electro-

negativity, dipole, intra-molecular and intermolecular

Used general terms instead of specific – e.g. ‘charged particles’, omitting reference to actual particles in the substance

Was unable to use appropriate phrases other than learned ones to show understanding e.g. ‘like dissolves like’

Lacked knowledge – e.g. ability to identify particle type in a substance; reactions and expected observations

Had contradictions in attempts to explain – structure and bonding

Was unable to accurately draw or name – organic compounds

Misunderstood – e.g. in bonding organic molecules, joined the oh group incorrectly

Was unable to structure answers coherently Used incorrect subscripts and superscripts Lacked understanding – e.g. significance of the

magnitude of the equilibrium constant; sign and unit: Iupac system

Showed confusion - e.g. between terms – reactants and products; left and right of the reaction

Unable to determine changes from data – e.g. enthalpy

Needed to understand ‘observation’ and principles involved

Did not do all parts of the question Wrote too much where it was not indicated,

much of it irrelevant or repetitive Did not complete diagrams e.g.

electrochemical cell Did not show understanding when asked to

‘explain’ a term or concept – sticking to words/terms in question

Tried to plug numbers into expressions, but discussion showing lack of understanding of chemical principles involved

Wrote contradictory statements Used a ‘recipe’ and given procedure to process

data with the frequent result that there was little evidence of understanding of results

Included inappropriate graphs Failed to link background material to

investigation Log books lacked detail Was unable to use significant figures

appropriately Was unable to differentiate between terms or

reactions- e.g. oxidation and reduction; clear/colourless;

Was unable to separate a balanced equation for oxidation-reduction reaction into two half equations

Lacked understanding – e.g. that one half reaction must gain electrons while the other must lose electrons; failure to react

Was unable to link – e.g. observations; – ionisation energy with electrostatic attraction between nucleus and the valence electrons



LEVEL 1 LEVEL 2 LEVEL 390172 Atomic structure and bonding Cannot clearly describe - differences between

atoms, molecules and ions; ionic bonding (using words like ‘swapped’ or ‘exchanged’ to explain what was happening to the electron when the bond was formed); breaking of forces of attraction

Inability to correctly identify symbol (beryllium) and so calculate

Inability to write electron configurations for ions

Inability to draw diagrams – lewis – often drew electron orbital diagrams instead, or failed to pair electrons

Unable to explain differences – in reactivity of atoms

Inability to define accurately – confusing sublimation and reverse sublimation; inter- and intra-molecular forces

Inability to use words – e.g. ion, molecule or attractive force - accurately in sentences

90173 Non-metals and compounds Unable to use knowledge from a diagram –

nitrogen cycle Unable to correctly describe properties –

density, solubility Lack of knowledge – colour and state for

chlorine, oxygen, sulphur Unable to complete and balance equations

Misunderstood question - e.g. when explaining the effect of a decrease in temperature, discussing the effect of increasing the temperature

Did not understand links – e.g. ph Unable to carry out simple equations Was unable to write correct formulae and

charge – e.g. on ionic species Was unable to balance equations correctly –

especially with respect to charge Was unable to identify species and describe

accurately – e.g. as oxidants or reductants Was unable to describe – e.g. experimental

observations for a reaction Lacked understanding of principles – e.g.

electrolysis

Was unable to describe characteristics – e.g. electrochemical cells

Was unable to use standard reduction potentials to predict the spontaneity of a reaction

Was unable to recognise – e.g. that both species in a redox couple cannot be identified as the oxidant; configuration

Was unable to draw lewis diagrams correctly – dots and/or lines to show bonded pairs

Lacked understanding – radius/size Used terms inaccurately – e.g. shielding,

effective nuclear charge Showed confusion between phosphorus-32

and element phosphorus Was unable to recall – e.g. colours of set

species Was unable to answer questions relating to

polymer formation or hydrolysis of peptides Was unable to use structural formulae inability

to focus accurately (functional groups) and consider (reagents needed)

Common misunderstandings were extensive Was unable to explain with equations Was unable to correctly manipulate data



LEVEL 1 LEVEL 2 LEVEL 390648 Carbon Inability to use appropriate terms – atom,

molecule Confusion of terms – soluble, insoluble Lack of knowledge – definition of polymer;

origin carbon dioxide in soft drinks Lack of understanding – polymer formation Inability to write clear answers to explain or

discuss Too much information given Factual errors


SPECIFIC DIRECTIVES TO TEACHERS

LEVEL 1 LEVEL 2 LEVEL 3 Students need to have learned what they are required to know from the standards – using all of the explanatory notes Ensure that the most recent version of the standard is being used Ensure that the level of direction laid down is followed Where groups are carrying out an investigation, ensure that each student can meet the requirements Assessment schedules need to have examples of expected evidence Ensure that the degree of difficulty allows for achievement at each level

Guide choice of relevant observation to a reaction – rote-learned observations not useful and misused

Ensure students know to answer all questions as there is an achievement component in all required for achievement

Ensure students understand that only one correct answer is required so that repeating information from the question is of no benefit

Ensure students clearly understand the difference between observation and inference

Discourage repeating the same observation with different wording

Students need to know the symbols for commonly used elements

Candidates need knowledge and understanding of chemical terminology and the ability to use this language appropriately and correctly

Candidates are expected to have carried out practical work, and to have knowledge of observations occurring during reactions and how these observations may be used to identify substances, if required

Students need to learn to use full sentences, not bullet points, for discussion and explanation-type questions

Candidates need to be able to apply their knowledge and skills to less familiar examples or contexts

Candidates need to be able to choose a good model of what a metal is in terms of the particles and the forces between these particles

Correct usage of symbols needs to be practised – e.g. cu and ag.

There were a lot of misunderstandings which are detailed in the general comments – specifics given e.g. term electro-negativity poorly understood and often inappropriately used

Chemical literacy is defined in detail – the ability to link macroscopic observations to the species involved, and to write balanced equations for the reactions involved

Three dimensions – macroscopic, symbolic, sub-microscopic – diagram – excellence sees confidence in all dimensions

Write fluently and concisely Ensure students are aware of the depth of

knowledge and understanding needed at this level – e.g. it will not be enough to simply name and identify

An important part of the examination technique is to remember to use information provided in an earlier part of the question

Need to set out calculations in a logical, stepwise sequence so ‘follow-on’ marking can be applied

Ensure students are familiar with the calculator they will use so they know how and when to use brackets when entering data – so the order of operations is correct

Be aware of the assessment specification illustration on how to draw three-dimensional structures of organic molecules


SPECIFIC DIRECTIVES TO TEACHERS

LEVEL 1 LEVEL 2 LEVEL 3 Students need to be able to discuss fully and

in specific terms – e.g. dissolving of substances

Need to know how to use a dash or pair of dots in a Lewis diagram

Students made good use of the assessment specifications where there were examples of acceptable methods of naming and drawing structural formulae

Students need to be able to read a burette to a higher level of accuracy than is always being given – e.g. to 0.05ml or 0.02ml

90697 – notes: ‘colour change’ involves a conversion from one colour (that of the reactant) to another (that of the product/s). Both of these colours need to be included in an answer

90697 – notes: the Lewis diagram of an ion needs to be enclosed in square brackets with the charge as a superscript

Extensive notes in many standards give detail of common misunderstandings, issues

Ensure students are operating at Level 3 and at the level of achievement for internal standards – e.g. showing evidence of critical thinking in discussions

Ensure that the purpose of investigations carried out are appropriate for Level 8

Ensure conclusions refer back to aims and purpose

Ensure that students are aware of suitable/sensible titre value


KEY VOCABULARY

Level 1 Level 2 Level 3Instructional words noted:describe, explain, discuss, elaborate, justify, relate, evaluate, compare, contrast, analyse, link, apply, carry out, use, interpret, solve,

90169primary data, investigation, aim, testable question, prediction, hypothesis, scientific idea, variable – independent, dependent, sample, sampling bias, sources of error, valid conclusion

90305 qualitative analysis, flow chart, process of elimination, ion, cation, anion, solution, concentration, precipitation, complex ion formation reaction, named pairs, experimental observation, balanced equation, complex ions

90694 quantitative, extended practical investigation, substance, standard solution, titration, precipitation, colorimetry, pre-calibrated measuring equipment, water test kit, dissolved oxygen meter, procedure, log book, raw data, trend, substance, significant variables, analytic technique, valid conclusion, reliability, significant figures, modification, validity, sources of error

90170sources of information, secondary information

90306 acid-base volumetric analysis, solution, concentration, titre, titration, burette, stoichiometry, concordant, value, significant figures

90695 titration, titre, solution, concentration, burette, oxidant, reductant, composition, dilution, limited/reasonable/high precision, mole ratio, volume

90171chemical reaction, oxidation-reduction, precipitation, thermal decomposition, reaction, redox reaction, molar mass, mass-mass, monatomic ion, mole ratio, atomic mass, atomic number, electron, molecular formula, substance, mass, insoluble/soluble, colourless/clear, reactant, product, compound, electron/oxygen transfer, interpretation, classification, reduction

90307 Gravimetric/Colorimetric 90696 oxidation, reduction, reaction, standard reduction potential, species, balanced and half equations, electrochemical cell, electrode potential, reactant, product, spontaneity, redox couple, titration analysis, mole ratio, stoichiometric calculations, interconversion


These are lists of key words taken from Assessment Reports and from the Achievement Standard explanatory notes. They provide a starting point for vocabulary work

KEY VOCABULARY

Level 1 Level 2 Level 390172 atomic structure, bonding, ion, ionic, atom, molecule, subatomic particles, monatomic, mass number, atomic symbol, periodic table, atomic structure, electron configuration, transfer, chemical reactivity, Lewis diagrams, proton, neutron, electron orbital diagrams, electron dot pair, bonding, covalent, ionic, sublimation, reverse sublimation, forces of attraction, inter- and intra-molecular forces, discrete molecules, charge, single/multiple bonds, ionic/covalent bonds, conductivity, melting/boiling point, molecular, compound, particle, separation, energy, motion, attraction, force, valence electrons, constituent particles, van der Waals forces

90308molecular, ionic, metallic, covalent network, dipole, periodic table, polarities of molecules, solids, ionic solids, melting point, Lewis structures, constituent particles, attractive forces, bonding, intra- and inter- attractive forces, polar bonds, bond polarity, electro negativity/conductivity, solids, solubility, polar and non-polar solvents, trends, periodic table

90697 atomic, molecular, ionic, electron configuration, valence electrons, shells, species, molecule, ion, atom, mass, nucleus, atomic size, ionisation energy, electro-negativity, electron density, molecular polarity, transition metals, isotope, element, decay, orbitals, electrostatic attraction, emission, Lewis diagrams, atomic radius, shielding, effective nuclear charge, reactant, product, repulsion, clear, colourless transition metal species, reaction

90173 non-metal, compound, oxygen, nitrogen, sulphur, chlorine, legume, nitrogen cycle, protein, acidic nature, aqueous solution, observation, deduction, chemical reaction, chemical properties, chemical species, reaction, physical properties, state, colour, solubility, density, oxidising properties, electrolysis, ammonia, hydrogen chloride, oxides, fractional distillation, chlorine gas, brine, sulphur/nitrogen dioxides, bleaching, antiseptic – sodium hypochlorite, sulphite ion, preservation, reductants, acid rain, ozone, depletion, Haber and Contact Processes, photochemical smog, balanced equation

90309organic compounds, functional group, IUPAC conventions, structural formulae,alcohols – primary, secondary, tertiary, classification, alkenes, alkanes, halo alkanes, alkyne, alcohol, ester, carboxylic acid, asymmetric, carboxylic acid, geometric (cis-trans) isomers, isomerism, addition reaction, substituents, multi-step reaction schemes, hydrolysis of triglycerides, functional groups, reaction products, condensed/expanded forms, polymerisation, halogenation, oxidation, elimination, formation, reaction, hydrolysis

90698 organic products, structure, reaction, compound, reaction scheme, acid-base, oxidation, elimination, substitution, esterification, hydrolysis, polymerisation optical and geometric isomers, reaction, reagent, aldehydes, an unsymmetric alkene, polymer formation, hydrolysis of peptides, polypeptides, structural and molecular formulae, functional groups, enantiomers, rotation plane, polarised light, constitutional isomers, enantiomers, IUPAC conventions, physical properties, reactions, solubility, melting/boiling points,Tollens’, Fehling’s, Benedict’s, reagent



KEY VOCABULARY

Level 1 Level 2 Level 390640properties, metal, acid, base, physical/chemical properties, element, compound, low density, reactant, reaction,universal indicator in common solutions, rust, corrosion, particle theory, collision, surface area, acidity, alkalinity, neutralisation, acid-base reaction, pH, conductivity – thermal/electrical, density, lustre, malleability, ductility, relative reactivity, extraction, ore, word/balanced equation, litmus, universal indicator, concentration, temperature, surface area, ions, iodic, atomic numbers. masses, symbols

90310thermochemical, equilibrium, exothermic, endothermic, significance, equilibrium constant expressions, magnitude of K2, enthalpy changes, catalyst, concentration, hydronium, pH, reaction rate, particle, reactant, product, observation, collision theory, collision frequency, reaction pathway/rate, conductivity, activation energy, acid solution, conjugate base, temperature, catalyst, pressure, homogenous system, dynamic, acid, base, proton transfer, aqueous solution, ionic species

90699 thermochemical, hydrogen bonding, bonding enthalpy, mass, moles, reactant,melting point, forces, intermolecular, intramolecular, Hess’s law, endothermic, exothermic process, change, enthalpy change, molar, fusion

90648 carbon cycle, allotrope, organic molecules, IUPAC nomenclature, combustion, atom, molecule, polymer, polymer formation, soluble, insoluble, carbon dioxide, acid, compound, inter/intra-molecular forces, alkanes, hydrocarbon, methanol, ethanol, ethanoic acid, ethene, propene, structural formulae, density, solubility, acidic nature, aqueous solution, combustion, reaction, lime water, carbon monoxide, melting/boiling points, separation, fractional distillation, fermentation, organic, global warming

90311 oxidation, oxidants, reductants, ionic species, experimental observations, electrode, electrolysis, ion movement, products, species, balanced equations, halogens, halide ions, electrolytic cells, preferential discharge

90700 equilibrium, aqueous systems, solubility, concentration, ion, species, buffer, acid, base, pH, salt, titration, equivalence point, dissociation, saturated, proton transfer reaction, soluble ionic solid, species, quantitative, qualitative, correlation, acid/base strength, dissolved, complex/common ion, titration curves buffer region, equivalence point, indicator, monoprotic acid, dissolution

90763quantitative, relationship, variable, molar/atomic masses, formulae, compound, composition, empirical/molecular formulae, mass of solid, standard solution, solid, moles, constant mass, hydrated salt, stoichiometric, crystallisation, concentration, titration



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