Solids, liquids and gases. In a solid like this brick, the particles are regularly arranged touching their neighbours and move only by vibrating. This explains why solids have a fixed shape. In a ...

Substances can exist in three states of matter - solid, liquid and gas. All substances are made from particles, and the forces between the particles are different in solids, liquids and gases. The ...

Students are introduced to the idea that matter is composed of atoms and molecules that are attracted to each other and in constant motion. Students explore the attractions and motion of atoms and ...