Elephant Toothpaste

This is a fun experiment that surprises everyone. After mixing up two concoctions of easily obtainable ingredients, a thick foam oozes and oozes out of  the bottle, looking like a giant toothpaste squeezed out of a giant toothpaste tube for a elephants toothbrush.


Ingredients
A clean 16 ounce plastic soda bottle. Narrow necked glass bottles can work as well.

1/2 cup 20-volume hydrogen peroxide liquid . It si called "Developer" in the beauty supply stores. 20-volume is a 6% solution, I used 30 and it worked great. You can use 40 (12%) or higher, but while it makes bigger reactions, it also generates more heat.  Kids would need more supervision and it might not be appropriate for younger kids to do it themselves.

1 Tablespoon (one packet) of dry yeast

3 Tablespoons of warm water

Liquid dish washing soap

Food coloring

Small cup

Safety goggles

NOTE: As you can see from the picture, foam will overflow from the bottle, so be sure to do this experiment on a washable surface, or place the bottle on a tray. One of those aluminum trays they put turkeys in works great.

1.Add the 1/2 cup of  Hydrogen peroxide to the bottle. It can irritate skin and eyes, so put on those safety goggles and ask an adult to carefully pour the hydrogen peroxide into the bottle.

2. Add 8 drops of your favorite food coloring into the bottle.

3. Add about 1 tablespoon of liquid dish soap into the bottle and swish the bottle around a bit to mix it.

4. In a separate small cup, combine the warm water and the yeast together and mix for about 30 seconds.

5. Now the adventure starts! Pour the yeast water mixture into the bottle (a funnel helps here) and watch the foaminess begin!

The foam is awesome! The foam made is special because each tiny foam bubble is filled with oxygen. The yeast acts as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since it does this very fast, it creates lots and lots of bubbles. The bottle gets warm. The experiment creates a reaction called an Exothermic Reaction - that means it not only makes foam, it creates heat! The foam produced is just water, soap, and oxygen so you can clean it up with a sponge and pour any extra liquid left in the bottle down the drain.

This experiment is sometimes called "Elephant's Toothpaste" because it looks like toothpaste coming out of a tube, but don't get the foam in your mouth!

Here's a video of how one guy did it: