Structured questions
Simple recall questions are usually worth one mark. They often have command words like 'Give...', 'State...', 'Name...' or 'Identify...'. Some questions may ask you to state two things, rather than just one, and will be worth two marks.
Structured questions, with command words such as 'Describe...' or 'Explain...', will be worth two or more marks:
- if you are asked to describe something, you need to give an account but no reason
- if you are asked to explain something, you must give reasons or explanations
More complex structured questions will be worth three or four marks. They include questions with complex descriptions and explanations, questions in which you need to compare and contrast two different things, or calculations with several stages.
The mark schemes given here may show answers as bullet points. This is to show clearly how a mark can be obtained. However, it is important that your answer is written in a logical manner, the points are linked to each other, and are relevant to the question.
Learn about command words with Dr Alex Lathbridge
Listen to the full series on BBC Sounds.
Understanding the different command words in your science GCSE exams.
Sample question 1 - Foundation
Question
When solid ammonium chloride is shaken with water, a colourless solution forms and the temperature changes from 20°C to 16°C.
Give the name of the type of heat change occurring.
[1 mark]
Edexcel question courtesy of Pearson Education Ltd.
Endothermic [1]
Sample question 2 - Foundation
Question
Zinc reacts with dilute hydrochloric acid to produce zinc chloride and hydrogen.
When zinc powder is used, instead of larger pieces of zinc, the reaction is faster.
Explain, using ideas about particles, why the reaction is faster when zinc powder is used. [2 marks]
Edexcel question courtesy of Pearson Education Ltd.
- zinc powder has a larger surface area [1]
- there are more frequent collisions between the particles [1]
Sample question 3 - Higher
Question
During any reaction, reactants are used up and the rate of reaction decreases.
Explain, in terms of particles, why the rate of reaction decreases. [2 marks]
Edexcel question courtesy of Pearson Education Ltd.
- fewer particles/as the reactants are used up there will be fewer particles to react/a lower concentration of particles [1]
- this will result in a lower frequency of collisions, so fewer particles reacting in a given time [1]
Sample question 4 - Higher
Question
Catalytic converters in the exhaust systems of cars contain catalysts.
Explain what is meant by the term catalyst. [2 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
- (a substance which) speeds up/increases the rate of (a reaction) [1]
- (but is chemically) unchanged (at end of reaction)/not used up (in reaction)/mass remains the same [1]
