All matter is described as being made from particles, which are too small to be seen and always moving. Solids are described as having particles which are close together and unable to move far and as having their own shape and being hard to compress. Liquids are described as having particles which are also close together but free to move and as taking the shape of their container and being hard to compress. Gases are described as having particles which are further apart and as having their own shape and being easy to compress.
Students could use this clip to explain the difference in properties of solids, liquids and gases and the behaviour of particles. Students could be challenged to list as many different types of solid, gas or liquid as they can, and if possible provide chemical formulae for them. For chemical compounds, students could suggest chemical equations for making those compounds.