The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook American Heritage Coll.
Condensation is the reverse of vaporization , or change from liquid to gas.
It can be brought about by cooling, as in distillation , or by an increase in pressure resulting in a decrease in volume. The explanation of condensation can be found in the kinetic-molecular theory of gases . As heat is removed from a gas, the molecules of the gas move more slowly, and as a result, the intermolecular forces are strong enough to pull the molecules together to form droplets of liquid. Similarly, reducing the volume of the gas reduces the average distance between molecules and thus favors the intermolecular forces tending to pull them together. The Columbia Encyclopedia, Sixth Edition.