Free-response questions
Free-response questions will appear throughout both exams papers (Breadth and Depth), and at both Foundation Tier and Higher Tier.
These questions provide answer lines for you to write your answer and may sometimes also provide a blank space for you to draw a diagram or show your working out.
The number of answer lines and the number of marks for the question are guides to the amount of detail to include in your answer. A question worth one mark with only one answer line probably only requires a one sentence answer, or perhaps just a single word or phrase. For questions with more marks and more answer lines you will have to go into more detail or give specific data points, eg:
- the speed of the object decreased (1 mark)
- the speed of the object decreased by 8 m/s (2 marks)
Free-response questions often start with a command word such as 'describe' or 'explain'. It’s important to understand the different types of answers required by 'describe' and 'explain'. As a rule of thumb:
- describe what happens, when and where
- explain how and why it happens ("it happens because…")
Other command words you might see include:
- 'write down' (give a short answer, without explaining it)
- 'suggest' (use your scientific knowledge and understanding to give a sensible answer in an unfamiliar context)
- 'compare' (write about the similarities and differences between two things)
- 'discuss' (write about the issues related to a topic, and talk about arguments for and against)
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
The element iodine has many isotopes.
A nucleus of the stable isotope of iodine can be represented as:
\(_{53}^{127}\textrm{I}\)
Outline the differences between the nuclei of two isotopes of the same element. [1 mark]
OCR 21st Century Science, GCE Physics, Paper J259, 2016.
Different nuclear mass/Different number of neutrons.
For this question all you need to do is state the difference between isotopes. It is acceptable to say that either the mass number or the number of neutrons varies for the mark.
Sample question 2 - Foundation
Question
Here is part of a leaflet given to patients of a local hospital:
"Safe and Painless Diagnosis for Kidney Patients:
You can obtain images of your kidneys using a radioisotope.The radioisotope quickly passes into your kidneys and then into your bladder and is then excreted. The radioisotope emits gamma radiation."
a) It is important that this radioisotope should have a short half-life. Suggest why. [2 marks]
b) Alpha and beta radiation are not suitable for obtaining images of inside the body. Explain why. [3 marks]
OCR 21st Century Science, GCE Physics, Paper J260, 2016.
a)(Gamma radiation) damages tissue in a patient.
(Short half-life) means small dose / less gamma radiation exposure.
In this question it's important to not get distracted by the context - in this case, the leaflet. Look at what is being asked then relate it back to the context. Radioisotopes used in hospital should have a small half-life in order to reduce exposure. They should also be a gamma source, as this will cause less tissue damage because they can pass straight out and are less ionising.
b)Alpha and beta are not very penetrating/easily absorbed.
Hence will not be detected outside body.
Absorption by body will damage tissues/cells.
The command word in this instance is explain, so you need to give detail in your answer for the three marks. Start by stating that alpha and beta are not very penetrating. Next, explain why this is an issue, eg it will not be detected outside the body. Then explain the dangers that it would cause if these were absorbed by the body.
