The atoms of a solid are strongly attracted to each other. Solids keep their shape because of these strong attractions. The atoms vibrate but do not move past each other.

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 this loose state, the particles move in clusters of increasing size." Incidentally, temperature changes play no role in ...