What happens to the properties of a gas as its temperature decreases, according to the kinetic molecular theory?

According to the kinetic molecular theory, as the temperature of a gas decreases, the average kinetic energy of its molecules also decreases. This relationship stems from the idea that temperature is directly proportional to the average kinetic energy of particles in a substance. As temperature drops, the energy that causes the particles to move and collide diminishes, leading to a reduction in their speed and kinetic energy.

In this framework, the kinetic energy is what governs the motion of gas particles, and therefore, when the temperature falls, the molecular motion becomes slower and less energetic. This results in a significant decrease in both the speed and kinetic energy of the molecules.

Other aspects such as the distance between gas molecules and their speed behave differently with temperature variations. As the gas cools, while the average kinetic energy decreases, the molecules do not necessarily move further apart; instead, they tend to come closer together due to reduced motion, which can lead to increased pressure if the volume is kept constant. Thus, the properties of gas molecules reflect a clear connection between temperature and their energies, aligning perfectly with the predictions made by the kinetic molecular theory.