This exciting science experiment works great in a discussion on reactions, as a demonstration, or as an actual experiment. To use it as an experiment, perform it once with your child, then ask your child what might happen if you changed the amounts or left out an ingredient. Let her direct the experiment! Also, the foam created is safe to touch. It is simply water, oxygen gas, and soap, so if your child has no soap allergies, she can experience and experiment with the texture of the foam!
How to make Elephant Toothpaste:
** 2 Tablespoons warm water
** 1 teaspoon yeast
** 1/2 cup 6% hydrogen peroxide. It is important to use at least 6%. You can use 8% or more (available on Amazon), or you can Salon Care Professional Stabilized Formula. 20 Volume Clear Developer from Sally Beauty Supply works fine too. 3% from the grocery store will NOT work as well. :)
** 4-5 drops food coloring
** squirt of dish soap
If you're working with older kids, you may be interested in how it works:
The reaction is summarized by this formula: 2 H2O2 --> 2 H2O + 02.
Hydrogen peroxide (H2O2) naturally breaks down into water and oxygen. It is stored in opaque containers to help slow down this process. Catalase (an enzyme in all living things, including yeast) speeds up the reaction. Dish soap catches the oxygen and makes bigger bubbles and the food coloring makes it look cool. The foam and bottle feel warm because the reaction is exothermic--it releases energy as heat.
UPDATE: At the request of many of you, I am providing these amazon affiliate links for 6% hydrogen peroxide for your convenience. You will not pay any more for them, but we will receive a small commission for referring you. I recommend buying a larger container because your kids will want to repeat the activity many times!