The Elephant Toothpaste experiment is a science experiment that demonstrates the rapid decomposition of hydrogen peroxide using potassium iodide or yeast and warm water as a catalyst. The reaction produces a large amount of foam that looks like toothpaste coming out of a tube, hence the name Elephant Toothpaste. The experiment can be done at home or in the classroom with simple materials such as an empty plastic bottle, hydrogen peroxide, yeast, dish soap, and food coloring. The steps to conduct the experiment are as follows:

1. Measure 1/2 cup of hydrogen peroxide and pour it into the bottle.
2. Add a few drops of food coloring to the hydrogen peroxide.
3. In a separate container, mix 1 tablespoon of yeast with warm water and stir until the yeast dissolves.
4. Add a few drops of dish soap to the yeast mixture and stir.
5. Pour the yeast mixture into the bottle with the hydrogen peroxide and quickly step back.
6. Watch as the reaction occurs and foam starts to pour out of the bottle.

The foam produced is just water, soap, and oxygen, so it can be cleaned up with a sponge and poured down the drain. The experiment can be modified by changing the concentration of hydrogen peroxide or the amount of yeast used to see how it affects the amount of foam produced. It is important to note that hydrogen peroxide can irritate the eyes, so safety goggles should be worn when conducting the experiment.