I have seen elephant toothpaste science experiments all over the place and have been wanting to do it with our boys for a while, but we just have never had all the ingredients that are needed. While at the Chemist getting a script, I was looking around and saw hydrogen peroxide. I knew I had seen that before and that it was needed for a science experiment, but couldn’t remember which one. I bought it and found that it was one of the ingredients in Elephant’s Toothpaste. We also needed a 450ml plastic bottle, which we found the morning we were doing the experiment, at the bakery down the road.
So for this experiment, you need:
- 450ml plastic bottle
- 1/2 cup of 20 volume (6%) solution of hydrogen peroxide liquid (I used a full 100ml bottle)
- 1 TBSP dry yeast
- 3 TBSP warm water
- 1 TBSP liquid dishwashing detergent
- food colouring
- small cup/bowl
- safety googles
This experiment can be quite messy, so we did it outside. You could do it on the table inside, but make sure you put the bottle in a tray of some sort, because the toothpaste does overflow!
Also, be careful when using hydrogen peroxide. I didn’t let my boys touch this, I carefully poured it into the bottle while they stood back as it can irritate your skin and eyes. And make sure you are wearing your safety goggles!
- First, pour the hydrogen peroxide into the 450ml bottle.
- Add about 8 drops of food colouring
- Add the dishwashing detergent and swirl the bottle a little to mix the ingredients so far.
- In a small cup or bowl, mix the yeast with the warm water.
- We used a funnel for the next bit to make it a little easier. Pour the yeast mixture into the bottle and watch what happens!
As you add the yeast mixture, you will notice that it starts to foam.
And the foam keeps coming out of the bottle and as it does, it looks like toothpaste coming out of a tube, which gives this experiment the name: Elephant’s Toothpaste!
How does this work?
When you added the yeast, it helped to remove the oxygen from the hydrogen peroxide. By removing this oxygen quickly, it created lots of bubbles. If you touch the bottle while it is foaming, you will notice it is warm. You have created an Exothermic Reaction as it creates foam and heat.