Which principle is observed when gas molecules collide elastically in a closed system?

The principle observed when gas molecules collide elastically in a closed system is rooted in the concept of ideal gas behavior, specifically characterized by the kinetic molecular theory. In this context, elastic collisions refer to the situation where there is no net loss of kinetic energy when gas molecules collide with each other or with the walls of their container.

Gay-Lussac’s Law, in particular, describes how the pressure of a gas tends to increase as the temperature increases when the volume is held constant. This principle connects closely with the behavior of gas molecules, where increased molecular activity (due to higher temperatures) leads to more frequent and energetic collisions with the walls of the container, thereby increasing pressure.

The other principles mentioned, such as Dalton’s Law, Charles’ Law, and Boyle’s Law, deal with different aspects of gas behavior. Dalton's Law pertains to the partial pressures of gas mixtures, Charles' Law relates to the direct relationship between the volume of a gas and its temperature, and Boyle's Law describes the inverse relationship between the pressure and volume of a gas, assuming constant temperature. While all these laws are significant in understanding gas behavior, the specific scenario of elastic collisions among gas molecules aligns best with the principles expressed by Gay-Lussac’s Law.