- Shallow containers or plates
- Cotton swabs
- Dish soap
- Liquid food coloring
- Milk (whole milk is best but any percentage will work)
- Pour the milk in a shallow container, just enough to cover the bottom. (Experiment with cold or room temperature milk.)
- Add drops of liquid food coloring to the milk, drop them close to one another in the center for a more dramatic effect.
- Dip a cotton swab in a small amount of dish soap and then very lightly touch it to the side of the color. Watch the liquid fireworks!
What is happening? Milk is mostly water but it also has proteins, minerals, and fat. The milk fat molecules are more dense than the liquid food coloring therefore the food coloring floats on top. The dish soap weakens the chemical bonds separating the water loving molecules and the water fearing parts of the molecules, flinging them apart and creating beautiful bursts of color. Keep experimenting, if the action slows down pour out the milk mixture into a spare container and start over with fresh milk.
Watch this project at: https://www.youtube.com/watch?v=Hh7iAMH59ZU&t=7s