Solid

Solid is one of the four common states of matter. The molecules in solids are closely bound together, so they can only vibrate. This means solids have a definite shape that only changes when a force is applied. This is different to liquids and gases which move randomly, a process called flow.

Solids can resist forces applied to their surface.

When a solid becomes a liquid, this is called melting. Liquids become solid by freezing. Some solids, like dry ice, can turn into gas without turning liquid first. This is called sublimation.