Phase Changes

Gas to Liquid

Condensation

When liquid water freezes, the average kinetic energy of its molecules _________________, and the arrangement of the molecules becomes more orderly.

Decrease

Gas to Solid

Deposition

What is the behavior of a substance during a phase change?

Either absorbs energy or releases energy.

A substance absorbs energy from its surroundings during a(n) ______________________ change.

Endothermic

As water freezes, it releases heat into its surroundings. Freezing is an example of a(n) _________________ change.

Exothermic

Liquid to Solid

Freezing

The energy absorbed by one gram of water as it changes from its liquid phase into water vapor is known as the _________________________________ for water.

Heat of Vaporization

The energy absorbed by one gram of ice as it melts is known as the ________ ___ _________ for water.

Heat of fusion

Solid to Liquid

Melting

The reversible physical change that occurs when a substance changes from one state of matter to another.

Phase change

Solid to Gas

Sublimation

What happens to the temperature of a substance during a phase change?

The temperature of a substance remains constant during a phase change.

True or False? Water molecules have a more orderly arrangement in ice than in liquid water.

True

True or False? When water vapor collects above the liquid in a closed container, the pressure caused by the collisions of this vapor and the walls of the container is called vapor pressure.

True

Liquid to Gas

Vaporization