Here's what you need:
- whole milk
- food coloring
- liquid dish soap
- pie plate
Pour the milk into the pie plate just enough to completely cover the bottom. Let it settle for a minute. Put a drop (or two) of each color of food coloring into the milk, near the center (but not on top of each other). Dip the end of your q-tip into the liquid dish soap and put that right into the center of the milk. Hold it there and watch the magic. Younger kids will want to stir it, but encourage them to just hold the q-tip in one place. Or pick up the q-tip and place it in another part of the plate to see what happens.
What is happening:
The fat and protein molecules in the milk are very sensitive to change. When you add the soap to the milk the molecules go crazy and move around. By adding the food coloring we can actually see how these fats and proteins act when combined with soap.
What happens if you try it in water or low-fat milk?
P.S. If any of you locals are ever interested in fun liquid nitrogen experiments (ice cream, perhaps?) let me know. I can totally hook you up!