Note the following about the diffusion of these two particles.
- Over short time periods, they never move very far. Clear the screen
each second and note how they almost never move more than 1/4 of the field
within this time.
- Given enough time, chances are the particles will "visit"
just about every area of the field.Wait 1 minute or more between screen
clears. During this time the pathways of the atoms will fill most of the
field.
- The area in which the atoms move expands with time, as a result of
the first two observations above.
- Except for the walls of the box, which constrain their movement, the
average position of the particles at equilibrium does not change with time.
The atoms undergo no net movement.