One to two mark questions will start with command words such as 'describe' or 'explain'. Some command words are easy to understand such as:
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 a steep linear increase for the first three hours 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 the form '[2 marks]'. It is essential that you give two different answers if a question is worth two marks. Sometimes you can gain a second mark by giving the units in a calculation or stating specific data points, eg 'The speed of the object decreased by 8 m/s.'
Edexcel questions courtesy of Pearson Education Ltd.
Describe what happens to wasted energy. [2 marks]
It is transferred  to the thermal energy store of the surroundings .
The figure shows a solar-powered charger for a mobile phone:
The screen of the solar cell takes in energy from the Sun.
State how energy is stored in a charger. [1 mark]
As a chemical energy store in the battery .