Now, this week it is all about choice making, we look into cool experiments where making the choice to add one material changes the entire outcome of the experiment. This experiment is called Elephant’s Toothpaste: why is it called elephant toothpaste? Well, the catalyst reaction makes HUGE foam like paste that looks like toothpaste, squeezing out of a tube. It is, of course, not toothpaste so we advise that you not try to brush your teeth with it!

To get started you going to need:

• 1⁄2 cup (120 ml) of 6% hydrogen peroxide liquid
• Tablespoon (25.5 g) of dry yeast
• 3 tablespoons (44 ml) of warm water.
• Liquid dishwashing soap
• Food colouring,
• 2 liter Plastic bottle

NOTE: The foam will overflow from the bottle, so be sure to do this experiment on a washable surface or place the bottle on a tray.

What to do:

1. Prepare yeast solution by adding dry yeast to warm water and wait a few minutes until it becomes frothy.
2. Pour 2 inches of hydrogen peroxide (6%) into the bottle.
3. Place bottle on a baking sheet.
4. Squeeze in a good squirt of dish soap.
5. Pour in yeast solution.

What is the science behind this:

For this experiment to work, you need a catalyst to jump-start a chemical reaction, in this case, we used Dry Yeast. 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.

What is a catalyst? A catalyst is some material that speeds up chemical reactions. Factories rely on catalysts to make everything from plastic to drugs. They help process petroleum and coal into liquid fuels. Natural catalysts in the body are known as enzymes —and are responsible for digestion and more.