Temperature, Heat, and Matter

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


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


melting: the change of a 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 attract each other.

freezing: the change of liquid into a gas.


boiling: the formation of bubbles of vapor that escape from a liquid that is being heated.


evaporation: the vaporization of molecules from the surface of a liquid.