You will complete eight required practical activities if you are studying GCSE Physics and twenty-one if you are studying GCSE Combined Science. You could be asked questions about the methods, safety precautions you might take, results and conclusions of these experiments.
There are two required practicals in the Particle model topic:
Edexcel questions courtesy of Pearson Education Ltd.
The figure shows an old brass mass marked with '500 g'.
a) A student puts the mass on an electronic balance. The electronic balance reading is 498.2 g. The student concludes that the electronic balance is not working properly.
Evaluate this conclusion. [2 marks]
b) The student wants to find the density of the old, brass mass. First he obtains a correct value for the mass. What else must he do to find the density? [3 marks]
a) With these types of question there is no mark for saying whether the student is right or wrong. You only get marks for your reasons - so pick the answer which you can see the best reasons for. For example:
The student is right because the balance might not be levelled or the battery in the balance might be running down.
The student is wrong because the mass could be worn or it could be within acceptable accuracy of the mass ± 2 g.
b) Measure the volume of the mass  by recording the volume of water it displaces in a measuring cylinder . Then use the equation .
A student investigates the density of a copper block and the density of a small stone.
The student calculates the volume of the block as 13 cm3.
She finds that the mass of the block is 100 g.
a) Calculate the density of the block. [3 marks]
The student found the volume of the copper block by multiplying the area of its base by its height.
The small stone does not have straight sides.
b) Describe how the student could measure the volume of the small stone.
You may use a diagram if it helps your answer. [3 marks]
b) Part fill a measuring cylinder with water and record the starting volume .
Completely immerse the stone in the water and record the final volume of water and stone . Volume of stone = final volume - initial volume .