Structured questions and short answer questions
Questions with 1, 2, 3 or 4 marks usually start with command words. If a question starts with the command word 'state', 'give', 'name' or 'write down', it needs a short answer only. This type of question can often be answered with one word or phrase.
It is important to state, give, name or write down the number of things that the question asks for. If you write down fewer, you cannot get all the marks. If you write down more, and one is wrong, you might lose a mark.
Learn about command words with Dr Alex Lathbridge
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Understanding the different command words in your science GCSE exams.
Some questions start with the command words 'describe', 'explain' or 'compare'. These are often worth two or more marks:
- Describe means you should recall facts, events or processes accurately. You might need to give an account of what something looked like, or what happened.
- Explain means you need to make something clear, or state the reasons for something happening. The points in the answer must be linked together. The answer must not be a list of reasons. All the points must be relevant to the question.
- Compare means you need to describe similarities and differences between things. If you are asked to compare X and Y, write down something about X and something about Y, and give a comparison. Do not just write about X only or Y only.
More complex structured questions will be worth three or four marks. They include questions with complex descriptions and explanations, and questions in which you need to compare things.
Some of the answers are shown here as bullet points. This is to show clearly how a mark can be obtained. However, do not use bullet points in your answers - the points must be linked together logically.
Sample question 1 - Foundation
Question
A fuel is made from pentane, hexane, heptane and octane. Describe how this fuel is different from crude oil. [2 marks]
This question is AQA material which is reproduced by permission of AQA.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
- The fuel is made from four hydrocarbons/compounds [1]
- And crude oil contains many more hydorcarbons/compounds [1]
Sample question 2 - Foundation
Question
Butane is used as a fuel in camping stoves.
a) Explain why butane can be used as a fuel. [1 mark]
b) Name the products made in the complete combustion of butane. [2 marks]
This question is AQA material which is reproduced by permission of AQA.
a) The combustion of butane releases energy. [1]
b) Carbon dioxide and water. [2]
Sample question 3 - Higher
Question
The cracking of decane, C10H22, makes three products when it is heated with a catalyst at 500 °C.
- C5H12
- C3H6
- C2H4
a) Write a balanced chemical equation for the cracking reaction of decane. [2 marks]
b) Give two reasons to explain why cracking is useful. [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) C10H22 → C5H12 + C3H6 + C2H4 [2]
b) Some products of cracking are used as fuels. [1]
Alkenes are used to make polymers (and many other useful substances). [1]
Sample question 4 - Higher
Question
During fractional distillation, why are hydrocarbons with larger molecules found in fractions which are produced lower down the fractionating column? [3 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.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
Longer/larger molecules have stronger intermolecular forces [1]
Therefore they have a higher boiling point [1]
And the temperature is higher lower down the fractionating column [1]
