Check out what happens when milk, food coloring, and dish soap create a cool chemical reaction with this experiment from the Nat Geo Kids book Try This! Extreme.
Once you're done, try it again using a small plate full of craft glue instead of milk. Let the glue dry and remove the glue disk from the plate for a visible souvenir of this experiment.
Fill the dish with about half an inch of milk.
Add dots of colors using food coloring. Make whatever pattern you like, but yse plenty of colorful dots.
Drop just one drip of dish detergent in the middle of the milk. Watch what happens! The colors will sink in response to the dish detergent, then emerge again—marbleizing and combining—before stabilizing and standing still
WHAT'S GOING ON
Milk is an emulsion, a suspension of fat droplets in water. This means they’re not mixed in, just hanging in the milk. Food coloring sits in drops in the water, too, making a stable system—until the dish detergent is added. Dish detergents are meant to separate out dirt or grease so they can be washed away. When the dish detergent is added, the suspension is broken up, and the fat droplets all rush to combine with each other, causing the blossoming of color.
After the colors marbleize, try to transfer the pattern onto a piece of paper. Drop the paper flat onto the milk’s surface and allow the liquid to soak it for a moment or two. Then lift the paper by several corners, flip it, and transfer to a paper towel to dry. Then spray it with Clear-Coat or another acrylic art spray to preserve the colors.