Elephant's Toothpaste

Time: 10 minutes

What you need:

• 3% hydrogen peroxide

• Warm water

• Yeast

• 12-16 oz. bottle

• Dish soap

• Food coloring

• 1 cup

• 1 tray

• Measuring cups and spoons

• Safety goggles

What you do:

1. Place the bottle on the tray, so that the chemical reaction is contained.

2. Pour a 1/2 cup of hydrogen peroxide into the bottle.

3. Add a heaping squirt of dish soap to the bottle.

4. Add a few drops of food coloring.

5. Pick up the bottle and swirl it to mix the soap and the coloring together

6. In the cup, combine 1 tablespoon of yeast and 3 tablespoons of warm water.

7. Take the spoon and stir for 30 seconds to fully dissolve the yeast.

8. Pour the yeast mixture into the bottle and watch a colorful, foamy, chemical reaction happen!

Questions to ask:

1. What did you observe when you mixed the ingredients together?

2. How long did the reaction take?

What's the science?

Hydrogen peroxide (H2O2) is a very unstable compound. It is constantly trying to break down into water (H2O) and oxygen (O2). When a catalyst like yeast is added to the hydrogen peroxide (H2O2), it makes the decomposition reaction occur very quickly. The yeast helps the oxygen separate from the water. The oxygen is then released as a gas, causing the bubbles to form inside the soap.

This is an exothermic reaction that releases heat. If you use a thermometer, you can see a slight increase in the temperature of the Elephant's Toothpaste once the reaction has happened!