Agnieszka Biskup - Super Cool Science and Engineering Activities: With Max Axiom Super Scientist

Citric acid, baking soda, and water react to produce carbon dioxide. The gas fills and inflates the bag. Because the reaction is endothermic, the liquid in the bag becomes cold to the touch. Once the reaction ends, the mixture returns to room temperature.

When it comes to chemical reactions, the most exciting ones are often exothermic reactions. They can produce energy as heatsometimes in surprising ways. Monster toothpaste is one exothermic reaction that never fails to wow a crowd.

small bowl

packet of dry yeast

3 tablespoons (45 mL) of warm water

clear plastic drink bottle

foil roasting pan

12 cup (118 mL) of 6% hydrogen peroxide*

liquid dish soap

food coloring

funnel

* found in beauty supply stores or hair salons

Put on gloves and safety goggles before trying this experiment. Hydrogen peroxide can irritate eyes and exposed skin.

Mix the yeast and warm water in a small bowl.

Set the mixture aside for about 30 seconds, or until the liquid becomes frothy.

Place the plastic bottle upright in the center of the roasting pan. Ask an adult to pour the hydrogen peroxide into the bottle.

Put two or three squirts of liquid dish soap into the bottle.

Add about 5 drops of food coloring to the bottle.

Gently swirl the bottle to mix the ingredients and return it to the center of the pan.

Using the funnel, pour the yeast solution from step 1 into the bottle.

Quickly remove the funnel, stand back, and watch the monster toothpaste ooze out!