posted by Anonymous .
Say you are observing a motional behavior of 40 Helium molecules. Keeping the basic concepts of the kinetic-molecular theory of gases in mind:
You follow one of the molecules with your eye. Over a lengthy period of time, does the molecule exhibit systematic motion, or is it random, chaotic motion? (The motion of a single gas molecule is characteristic of the process called diffusion.)
Individual molecules would exhibit Brownian movement.