5070 · O-Level
Chemistry command words
Chemistry equations and state symbols are non-negotiable on Explain and Calculate responses.
Recall — short factual answers
State / Give / Name
Give a short, factual answer — a term, value or example — with no explanation.
- What earns the marks
- A correct word or phrase is enough; extra detail wins no more marks.
- Common mistake
- Over-writing a one-mark recall question and wasting time.
Define
Give the precise meaning of a term.
- What earns the marks
- Marks for an accurate definition that matches the syllabus wording.
- Common mistake
- Giving an example instead of the actual definition.
Identify
Select or point out something from information given.
- What earns the marks
- Marks for naming the correct item — often from a source, graph or scenario.
- Common mistake
- Explaining when the question only asks you to pick out the answer.
Understanding — show you grasp the idea
Outline / Describe
Set out the main features or points, without giving reasons.
- What earns the marks
- Marks for each correct, relevant point or stage — say what, not why.
- Common mistake
- Drifting into explanation and running out of time on later questions.
Explain
Set out the reasons or causes (the "why" and "how") and make relationships clear.
- What earns the marks
- Marks for developed reasoning — because… therefore… so that… — not just statements.
- Common mistake
- Describing what happens instead of explaining why it happens.
Application — use knowledge in context
Calculate
Work out a numerical answer, showing your working.
- What earns the marks
- Method marks for the correct approach; accuracy marks for the right value with units.
- Common mistake
- Writing only a final answer — no working means no method marks if it is wrong.
Suggest
Apply your knowledge to a new context, or propose a reasoned idea where there is no single fixed answer.
- What earns the marks
- Marks for a sensible, applied response that fits the scenario.
- Common mistake
- Giving a generic textbook answer that ignores the context in the question.
Apply
Use a concept, method or theory in a particular situation.
- What earns the marks
- Marks for linking the idea explicitly to the data, case or scenario given.
- Common mistake
- Stating the theory without connecting it to the specific context.
Analysis — break down and connect
Analyse
Examine in detail, breaking something into parts to show meaning, causes or relationships.
- What earns the marks
- Marks for chains of reasoning that connect cause to effect or part to whole.
- Common mistake
- Listing points separately instead of developing and linking them.
Compare
Identify similarities and differences between two or more things.
- What earns the marks
- Marks for explicit comparative points — "whereas", "both", "unlike" — not two separate descriptions.
- Common mistake
- Describing each item in turn and leaving the comparison implied.
Evaluation — judge with evidence
Discuss
Write about an issue from more than one point of view, considering arguments for and against.
- What earns the marks
- Marks for balanced, developed argument across different viewpoints.
- Common mistake
- Arguing only one side, or listing points with no development.
Evaluate
Judge or weigh up the quality, importance or success of something, then reach a supported conclusion.
- What earns the marks
- Top marks need both sides weighed AND a justified judgement or conclusion.
- Common mistake
- Giving points on both sides but never reaching a conclusion — this stays mid-band.
Assess
Make an informed judgement about the importance or value of something, supported by evidence.
- What earns the marks
- Marks for prioritising factors and explaining which matter most, and why.
- Common mistake
- Treating every factor as equally important with no judgement.
Justify
Support a case, choice or decision with evidence and reasoned argument.
- What earns the marks
- Marks for reasons that defend your position and address the alternative.
- Common mistake
- Stating a decision without giving the evidence that backs it.
To what extent
Judge how far a statement is true, weighing supporting and opposing evidence.
- What earns the marks
- Top marks need a clear degree judgement ("largely", "only partly") with justification.
- Common mistake
- Answering yes/no instead of how far, or omitting the degree of agreement.