During Science lesson last week we made elephant toothpaste.

We needed:

• A clean plastic bottle
• 1/2 cup 6% hydrogen peroxide liquid
• 1 Tablespoon (one packet) of dry yeast
• 3 Tablespoons of warm water
• Washing up liquid
• Food colouring
• Small cup
• Safety goggles

We watched a video first and knew the foam would overflow from the bottle, so we carried out this experiment outside the classroom and placed the bottle on a tray.

What we did:

1. Hydrogen peroxide can irritate skin and eyes, so we carefully poured the hydrogen peroxide into the bottle.
2. We added 8 drops of your favourite food colouring into the bottle.
3. We added about 1 tablespoon of washing up liquid into the bottle and swished the bottle around a bit to mix it.
4. In a separate small cup, we combined the warm water and the yeast together and mixed it for about 30 seconds.
5. Then the adventure started! We poured the yeast water mixture into the bottle (using a funnel) and watched the foaminess begin!

How did this happen?

Foam is awesome! The foam we made is special because each tiny foam bubble is filled with oxygen. The yeast acted as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since it did this very fast, it created lots and lots of bubbles.

This experiment is sometimes called “Elephant’s Toothpaste” because it looks like toothpaste coming out of a tube, and it makes enough to brush elephant’s teeth.