10.7 Changes of State Vocabulary

Change of state

The transformation of one state of matter to another, for example, solid to liquid, liquid to solid, liquid to gas.

Melting point (mp)

The temperature at which a solid becomes a liquid (melts). It is the same temperature as the freezing point.

Melting

The change of state from a solid to a liquid.

Freezing

A change from liquid to solid.

Freezing point (fp)

The temperature at which a liquid changes to a solid (freezes) and a solid changes to a liquid (melts).

Heat of fusion

The energy required to melt exactly 1 g of a substance at its melting point.

Evaporation

The formation of a gas (vapor) by the escape of high-energy molecules from the surface of a liquid.

Boiling point (bp)

The temperature at which a liquid changes to gas (boils) and gas changes to liquid (condenses)

Boiling

The formation of bubbles of gas throughout a liquid.

Condensation

The change of state from a gas to a liquid.

Heat of vaporization

The energy required to vaporize 1 g of a substance at its boiling point.

Heating curve

A diagram that illustrates the temperature changes and changes of state of a substance as it is heated.

Cooling curve

A diagram that illustrates temperature changes and changes of state for a substance as heat is removed.

Sublimation

The change of state in which a solid is transformed directly to a gas without forming a liquid first.

Deposition

The change of a gas directly to a solid; the reverse of sublimation