Six-mark questions
Six-mark questions are often the questions that people find the most difficult. In all longer answer questions, but especially the six-mark ones, it is important that you plan your answer and not just rush into it. After all, you would plan an essay or short story before starting. Without a plan it is easy to stray away from the key point and lose marks, get steps in a process in the wrong order or forget key bits of information.
Six-mark questions will start with command words such as 'describe' or 'explain'. The command words 'describe' and 'explain' can be confusing. If you are asked to describe a graph, you will be expected to write about its overall shape, whether it is linear or curved, the slope of gradients etc. If you are asked to explain why a pattern or trend is seen in a graph, you will be expected to use your science knowledge, not just say what you see (which is a description), eg 'The graph shows the number of radioactive nuclei decreases as time increases. It does this because鈥'.
Explain how and why questions often have the word 'because' in their answer. Describe questions don't.
The number of marks per question part is given in this form: '[6 marks]'. It is essential that you give as many different points in your answer as possible, linking these together. Often, you will be asked to compare two things: make sure that you include both in your answer, otherwise you are likely to limit your score to two marks out of six marks.
Edexcel questions courtesy of Pearson Education Ltd.
Writing six-mark answers with Dr Alex Lathbridge
Listen to the full series on 大象传媒 Sounds.
How to write six-mark answers in your science GCSE exams.
Sample question 1 - Foundation and Higher
Question
The radiation badge contains a photographic film which is sensitive to radiation.
The radiation badge is sent to a laboratory after a month and the film is checked.
Explain how the badge shows the amount of different types of radiation that the radiographer has been exposed to. [6 marks]
There might be alpha, beta, gamma radiation as well as X-rays. Where radiation is absorbed by the film, it becomes darker. Different areas of the film are exposed to different types of radiation. This is because alpha particles are likely to be blocked by the paper and so won鈥檛 affect the film at all. Beta particles are absorbed by aluminium so will only reach the top part of the film. Gamma rays will be partially blocked by the lead but will affect all of the film.
Plan the key points that you should include in your answer. Consider the different types of radiation, and their effect on the film. Then consider why the different types of radiation might not all reach all parts of the film.
Sample question 2 - Foundation and Higher
Question
Neutrons are released during nuclear fission.
Describe how the neutrons released in nuclear fission are used to produce a controlled chain reaction in a nuclear reactor. [6 marks]
The neutrons released go on to collide with other nuclei which causes them to become unstable. The nuclei split into daughter nuclei and release more neutrons and energy. A moderator is needed because neutrons need to be slowed down to increase chance of collision. Graphite or water are often used as moderators. Control rods are used because the number of neutrons available for collision needs to be controlled so that reaction proceeds at a steady rate. Control rods made of boron can be used to absorb neutrons.
Plan the key points that you should include in your answer. Consider the process of fission itself making sure you refer what starts it, what happens to the nuclei involved and the role of neutrons released. Then consider how the reaction is controlled with a moderator and control rods.