The gas particle animation, using pink and green particles, illustrates how this behavior results in the spreading out of gases (entropy).

This situation can be described by first restricting attention to a single gas particle, and approximating the rest of the gas by a spherically symmetric distribution.

The volume of the balloon in the video shrinks when the trapped gas particles slow down with the addition of extremely cold nitrogen.

Effectively, the cavity restricts the movement of the gas particles, decreasing the thermal conductivity in addition to eliminating convection.

Kinetic energy added (endothermic process) to gas particles by way of collisions produces linear, rotational, and vibrational motion.