Using kinetic theory of gases to explain absolute zero temperature
Absolute zero is defined as the temperature at which the molecules have their lowest possible kinetic energy. According to kinetic theory of gases, molecules of a gas have an average speed which increases with temperature. So, as a gas is cooled, its molecules move more and more slowly and hence their kinetic energy decreases more and more. A point is reached when the molecules are assumed to come to rest and their kinetic energy becomes zero. At this point the gas has the lowest possible temperature called absolute zero.