Elephant's Toothpaste
Grade Level: 5
Strand: Understanding Matter and Energy
Topic: Properties of and Changes in Matter
Specific Expectations:
 Grade Five: (Science and Technology – Understanding Matter and Energy – Properties of and
Changes in Matter – Understanding Basic Concepts) – Expectation – Identify indicators of a
chemical change (e.g. Production of a gas).
 Grade Five: (Science and Technology – Understanding Matter and Energy – Properties of and
Changes in Matter – Understanding Basic Concepts) – Expectation – Explain how changes of
state involve the release of heat or the absorption of heat.
Required Materials:
 16 oz. empty plastic bottle
 ½ cup of hydrogen peroxide (3% formula)
 A squirt of Dawn dish soap
 food colouring
 1 teaspoon of yeast dissolved into 2 tablespoons of warm water
 2 Dixie cups
 Foil pan
 scissors
 measuring cups (½ cup, tablespoon, teaspoon)
Procedure:
1. Show students materials used to create this experiment. Ask them to predict what the reaction
will be between the hydrogen peroxide, dish soap and the yeast.
2. Stand up the plastic bottle in the middle of the foil pan.
3. Measure out ½ cup of hydrogen peroxide and pour into bottle.
4. Add a few drops of food colouring to the peroxide.
5. Add a squirt of Dawn dish soap to the peroxide and food colouring mixture.
6. In a separate cup, measure out 1 teaspoon of yeast and dissolve in 2 tablespoons of warm water.
7. Pour the yeast and water mixture into the plastic bottle and watch the reaction!
Scientific Explanation:
Hydrogen peroxide is an acid with oxidizing properties. The molecular formula is H2O2,
meaning it has two hydrogen and two oxygen molecules. By adding the yeast as a catalyst one of the
oxygen molecules is released and the hydrogen peroxide is decomposed to water and oxygen. The
water from the decomposition combines with the soap to create foam, and the oxygen gas from the
decomposition pushes the foam out of the bottle.





H2O2
(add yeast)




H2O





O1
(plus soap)
 

foam
gas wants to be released
This chemical reaction is exothermic; there is more energy released than used and this extra
energy takes the form of heat. Consequently, the foam that is pushed out of the bottle is warm to the
touch.
Glossary:
 Catalyst- a substance that initiates or accelerates a chemical reaction without itself being
affected (for example, the yeast remained the same but was essential to the reaction).
References:
http://www.stevespanglerscience.com/experiment/elephants-toothpaste
http://www.regent.edu/acad/schedu/pdfs/mcms/elephant_toothpaste.pdf
http://www.using-hydrogen-peroxide.com/elephant-toothpaste.html
Opportunities/Other Considerations:
 Always remember to use safety goggles when working with chemicals!
 Try using a higher concentration of hydrogen peroxide- 6% or higher creates a bigger reaction.
 Try doubling the ingredients- foam is less thick but more is produced.
 Try experimenting with different amounts of the required materials- see what happens!