How To Make A Foaming Fountain Of Elephant's Toothpaste

Science experiments that make everyone go "Ooh" and "Aah" are always a big hit, and this foaming fountain of 'Elephant's Toothpaste' is one of the best.

Elephant toothpaste is such an easy experiment to do, but the results are spectacular (think foamy water feature)! This is the perfect way to make home science lessons fun and memorable. For more science experiments you can do at home, many of them using household items, check out these great ideas for young kids and teens.

This is an impressive experiment, but be aware that the contents will overflow the bottle and may expand more than you expected! Make sure you conduct the experiment where it can’t stain or damage anything, and on a surface that is easily cleaned. Place it on a tray or take the experiment outside. Also, be aware that the hydrogen peroxide used in the experiment can irritate the skin, so we suggest that safety goggles and gloves are worn. The foam should not be touched with bare hands due to the hydrogen peroxide but don't let that put you off! This experiment is perfectly safe if the right precautions are taken.

Safety goggles.

Gloves.

A bottle of 6% or 9% hydrogen peroxide liquid (this can be found in most chemists).

1 teaspoon washing up liquid.

1 tablespoon dry yeast.

3 tablespoons warm water.

Food colouring (you could also use paint).

Empty plastic water bottle.

A tray.

1.Put on your goggles and gloves.

2.Put the funnel into the top of the water bottle, add 200ml of hydrogen peroxide.

3.Dribble a few drops of food colouring down the side of the bottle.

4.Add the washing up liquid and then swirl the bottle around carefully to mix the two liquids together.

5.Next, mix the yeast with some warm (not hot) water.

6.Now it’s going to get exciting! Add the yeast mixture to the bottle, take away the funnel and stand back!

So, how does this work? The yeast is the catalyst (it increases the rate of a chemical reaction without undergoing any permanent chemical change of its own). It makes the hydrogen peroxide break down into water and oxygen. And because this produces a large amount of oxygen, this speedily makes its way out of the bottle. The soapy water, which is from the washing up liquid combining with hydrogen, catches the oxygen, making bubbles, and this turns into foam. You will notice the bottle is warmer than when you started - this is because you created an exothermic reaction when the hydrogen peroxide was breaking down. An exothermic reaction means the energy created by the chemical reaction is transferred to the surroundings (in this case the bottle) and causes the temperature to increase!

If you want to make this experiment look like real toothpaste, try dribbling red and blue food dye down opposite sides of the bottle to make the bubbles and foam multicoloured!

Older kids can turn this into a more formal experiment by writing up the ingredients and method, then recording the results. Try using different colour combinations, and recording the way in which the 'toothpaste' forms when it foams out of the bottle.

Younger kids can use a less strong solution of hydrogen peroxide (3%) if you can get hold of it. If this is not possible, you can conduct the actual experiment for them. They will still be thrilled by the giant foaming fountain of Elephant Toothpaste that appears!