To help explain the differences between solids, liquids and gases we need to look closely at what they are made of. Scientists have found that all materials are made of very, very tiny particles. These particles are so small that we can’t see them with our eyes or even a microscope.
We can explain why solids, liquids and gases are different from one another using ideas about particles:
- how near they are to each other – when particles are close together they attract each other. This affects the behaviour of solids, liquids and gases.
- the way that they move – when we heat a material, its particles move faster or more vigorously.
This course is divided into three main modules: Density and Pressure; Change of State; and Ideal Gas Molecules.
The first three modules each have an assessment topic which you can use to check your understanding of the module’s content. You need to achieve the pass mark in each of these in order to attempt the final assessment. You can, however, try each of these assessments as many times as you wish.
(NOTE: Whilst this course is based on the Edexcel IGCSE syllabus, the bulk of its content is applicable to other IGCSE and GCSE curricula. It is a useful course for anyone who needs some additional input, delivered in a different way and with some questions to try!)