There are three states of matter;
solid, liquid and gas
Substances can change from one state to another. Kinetic theory can explain the change of state by considering all matter (substances) to be made of particles.
- solid, particles are closely packed in a regular arrangement. The particles vibrate about a fixed position.

- liquid, particles are closely packed in a random arrangement. The particles can move through the liquid but they cling together.

- gas, The particles are far apart. There motion is random and independent of the other particles.

