This movie shows how particles diffuse over time. At first, there is a concentration gradient setup between the two sides of the container, but as the particles diffuse this gradient goes to zero. Notice that even when the gradient is gone, the particles are still moving from one side of the container to the other, but there is no net flow.
To view the movie, click on the "play" button on the left of the bar under the picture. This button can also be used to pause the movie while it is playing. The buttons on the right of the bar under the picture can be used to advance or rewind the movie one frame at a time.
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