What is the primary factor that allows for the ideal gas assumption?

The ideal gas assumption is primarily based on the behavior of gases at high temperatures. At elevated temperatures, the kinetic energy of gas molecules increases significantly, resulting in more effective and frequent collisions between them. This enhances the conditions under which gases behave more ideally, meaning they adhere closely to the gas laws described by the ideal gas equation (PV=nRT).

As temperature rises, the intermolecular forces become negligible because the average distance between the gas molecules increases as they move more rapidly. This allows their behavior to approximate that of an ideal gas, where interactions other than elastic collisions are minimal or non-existent. The assumptions required for ideal gases—such as negligible volume of the particles themselves and no intermolecular forces—are thus more valid at high temperatures, where these factors have a diminishing effect.

In contrast, lower temperatures can lead to increased intermolecular forces and a decrease in kinetic energy, making gas behavior deviate from the ideal gas law as the particles begin to behave more like liquids or solids. High pressure can also lead to deviations from ideality due to the increased volume occupied by the gas molecules themselves becoming significant compared to the volume of the container. Therefore, high temperature is the primary factor that reinforces the validity of the ideal gas approximation.