What is the relationship between gas particle size and the distance between them?

In gases, the relationship between particle size and the distance between them is characterized by the fact that gas particles are much smaller than the distances that separate them. This is a fundamental aspect of the kinetic molecular theory, which states that the volume of the individual gas particles is negligible compared to the volume of the container they occupy.

Because gas particles are widely spaced apart, they do not interact significantly with one another except during collisions, which occur infrequently. This large distance allows for a low density and high compressibility of gases, as there is ample space between particles for them to move freely and spread out when pressure is released or temperature is increased.

This understanding explains why gases expand to fill their containers completely, unlike solids and liquids that maintain a fixed volume. Therefore, the notion that gas particles are much smaller than the distances between them accurately represents this behavior and aligns with established scientific principles regarding gas behavior.