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…'.
'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.
After going to the shops, a car driver places a bag of shopping on the passenger seat. During the journey home, the driver has to use the brakes to stop very suddenly. The driver is wearing a seat belt.
Explain what happens next to the car, the driver and the shopping bag. [6 marks]
An Edexcel question courtesy of Pearson Education Ltd.
Brakes apply a force to the car . This force from the brakes makes the car decelerate . A force also acts on the driver from the seat belt  so the driver decelerates at same rate as the car and they stay in the driving seat . No horizontal force acts on the shopping bag , so the shopping bag continues at same velocity until it falls off the seat .
Plan the key points that you should include in your answer. State the forces acting on the car and then explain what happens to the motion of the car. State the forces acting on the driver and then explain what happens to the motion of the driver. State the forces acting on the shopping bag and then explain what happens to the motion of the bag.