Temperature, heat, and matter

Thermal expansion: the expansion of matter when its tempeture is raised.


Preassure: the force on each unit of area of a surface.


Melting: the change of solid into a liquid.


Vaporization: the change of a liquid to a gas as molecules break free from each other.


Condensation: the change of a gas into a liquid as molecules attrack each other.


Freezing: the change of a solid into a liquid.


Boiling: the formation of bubbles of vapor the escape from a liquid that is being heated.
Evaporation: the vaporization of molecules from the surface of a liquid.