Which condition does NOT apply to an ideal gas?

An ideal gas is defined under several assumptions that facilitate the study of gas behavior under various conditions. One of these assumptions is that the individual gas molecules themselves have negligible volume compared to the volume of the gas as a whole. This means that the presence of the gas molecules does not take up significant space, allowing for the simplification of equations of state, such as the Ideal Gas Law.

When we consider this, the condition that the gas molecules have significant volume fundamentally contradicts the definition of an ideal gas. By ignoring the volume of the individual molecules, we simplify the interactions and behaviors of the gas, allowing us to better understand its properties in different scenarios.

The other conditions that define an ideal gas include the notion that gas molecules do not attract or repel each other, they are in constant and random motion, and they undergo elastic collisions, meaning that there is no net loss of kinetic energy during collisions between gas molecules or between molecules and the walls of their container. All these assumptions together help characterize ideal gas behavior, while the assumption of significant molecular volume directly opposes this concept.