1 pie plate, whole milk (about a cup), 3-4 different colors of food coloring, 1 bottle of liquid soap
Fill the pie plate with milk and allow it to come to room temperature. With your child, add a few drops of food coloring to milk. Help your child put a single drop of liquid soap in the middle of the plate and watch your milk colors explode!
Throughout the activity, ask things like: “How much milk should we use?”; “What colors do you want to add?”; “How many drops of blue are you going to use?”; “What do you think will happen?”
Why this works: milk contains fats and proteins. Any change in the solution (such as adding soap) affects these fats and proteins, making them twist, bend, and change into all kinds of shapes. The soap weakens the surface tension, which is the watery skin that holds the liquid’s molecules together. When the molecules move, they mix the colors. Ask your child, “What happened to the colors?”; “Do you see new colors now?”; “Why do you think the colors move?”