Structured questions
Structured questions with one to four 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
Listen to the full series on BBC Sounds.
Understanding the different command words in your science GCSE exams.
Some structured 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 to four marks. They include questions with complex descriptions and explanations, and questions in which you need to compare things.
The mark schemes given here show some answers 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 valid 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
Describe the differences between cracking and distillation. [2 marks]
This question is AQA material which is reproduced by permission of AQA.
The following are valid 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.
- cracking involves a catalyst [1]
- distillation does not [1]
Or...
- distillation does not involve a chemical reaction [1]
- but cracking does [1]
Sample question 3 - Higher
Question
Describe how ethanol can be made by the fermentation of glucose. Use a word equation in your answer. [4 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 valid 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.
Glucose → ethanol + carbon dioxide [1]
Plus any three from the following:
- temperature of approximately 40°C
- yeast
- no air
- sugar/glucose is dissolved in water
[3]
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 valid 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]
