When things mix without being stirred, it is called diffusion. Temperature can affect how fast atoms and molecules mix with each other. The water in each glass was a different temperature.When you can see things diffuse, you are watching molecules and atoms in motion. Heat can make atoms and molecules move faster. We used colored molecules in this experiment so it would be easy to see them move through the colorless water. But atoms are moving all the time, even when you can’t see them.