How is average kinetic energy related to temperature?

The average kinetic energy of molecules in a substance is directly proportional to its temperature. This relationship arises from the kinetic molecular theory, which states that temperature is a measure of the average kinetic energy of the particles in a substance. When the temperature increases, the energy of the particles increases, causing them to move more rapidly. Conversely, if the temperature decreases, the kinetic energy of the particles decreases, leading to slower movement.

This concept is fundamental in understanding how heat transfer and temperature changes affect substances on a molecular level. The direct proportionality implies that doubling the temperature (in Kelvin) will result in a doubling of the average kinetic energy of the particles. This relationship is critical in various chemical processes, especially in thermodynamics, where temperature changes play a significant role in reaction rates and energy exchanges.