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elephant toothpaste

STEAM for Kids: Elephant Toothpaste

This neat elephant toothpaste experiment will resemble what happens when you squirt out toothpaste from a tube – in foam form!

Disclaimer: Because a high concentrated level of hydrogen peroxide is being used, we recommend wearing safety goggles as it can irritate skin and eyes.  We also recommend an adult to do the pouring of this liquid. This experiment makes quite a bit of foam, so a washable surface or tray is recommended.

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  • Cylinder vase (or 16 oz plastic soda bottle will work,too)
  • Safety goggles
  • ½ cup 20 volume concentrated hydrogen peroxide Do not use 3% drug store hydrogen peroxide – anything lower than the above will not work for this experiment. We picked up ours at a local beauty supply store
  • Dish soap (any will do)
  • 3 Tablespoons warm water
  • 1 package (or 1 Tablespoon dry yeast)
  • Food coloring


Add the ½ cup of hydrogen peroxide to the cylinder vase or bottle.

Add a few pumps (1 Tablespoon about) of dish soap to the hydrogen peroxide. Swish around.

Add food coloring of choice, about eight drops.

Combine warm water and dry yeast. Stir for thirty seconds.

Pour the yeast mixture into the cylinder and watch out! Initially we did this experiment with 3% hydrogen peroxide and discovered there was no reaction, so you want to be sure you have the higher concentration.

So, what happened? What made the foam occur so suddenly when the yeast was added?

The yeast acted like a catalyst (helper) to remove the oxygen from the hydrogen peroxide. Since this was done so fast, it created a lot of bubbles. The bottle should have gotten warm as well. This was not due to the warm water you used – the experiment caused it! The experiment created a reaction called an exothermic reaction; which means not only did it create foam, it also created heat!

Since the foam produced is made of oxygen, water and soap, it can be cleaned up and poured down the drain.

Find more projects like this on our Pinterest page!

Photographs and content by: Heather Kucenski


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One Comment

  • Mel Jenkins says:

    So which is the correct amount of water…..3 Tbsp or the half pot shown in the picture?

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