Monster toothpaste science experiment

Monster toothpaste science experiment

Big messy science experiments are a fun way to get your kids interested in how things work. This 'monster toothpaste' science experiment for kids is a great hands-on learning activity.

What you need:

  • sheets of newspaper (to catch the mess)
  • 1 x empty soda bottle
  • 1 x tsp yeast
  • 2 x tbs warm water
  • a plastic funnel (to stop spillage)
  • 1/2 cup hydrogen peroxide (at least 6 percent, available at pharmacies)
  • 4-5 drops of food colouring
  • a squirt of dishwashing liquid


Number of players:


Place the empty bottle in the centre of the sheets of newspaper.

In a small jug mix together the yeast and warm water. Agitate it until bubbles form (you need to activate the yeast).

Use a funnel to pour 1/2 cup of hydrogen peroxide into the soda bottle. Add some food colouring and a squirt of dishwashing liquid.

Now add the yeast mixture to the bottle.

Watch the monster toothpaste rise up and ooze out of the bottle.

Why is it so?

For science geeks, the reaction is summarised by this formula: 2 H2O2  –>  2 H2O + 02. 

That's interesting. But what does it mean in words?

Hydrogen peroxide naturally breaks down into water and oxygen. The yeast speeds up the reaction. Dish soap catches the oxygen particles as they are released by the 'breakdown' process and forms bigger bubbles. The foam and the bottle feel warm because it is an 'exothermic' reaction: meaning it releases energy as heat.

Whatevs man, it just looks totes awesome!

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