1- Introduction:
We chose elephant’s toothpaste as our science experiment to show how
energy (heat) can be released through chemical reaction. Every step in this
experiment will illustrate a chemical change. A chemical reaction is a process
that leads to the transformation of one substance to a new one. The
substances that are reacting are called reactants; the new substances formed
are called products. This experiment created a reaction called an exothermic
reaction that means it not only created foam but also heat. So, an exothermic
reaction is a chemical reaction that releases energy through light or heat.
We will study the chemical and physical effects of combining hydrogen
peroxide and yeast to produce new substances and different states of matter
such as liquid, solid and gas in a colorful and fun demonstration. It also
focuses on the use of catalysts and the explanation behind why we use them.
2- Materials used for this experiment:
we used a water bottle, hydrogen peroxide, liquid dish soap, food
coloring, yeast, warm water, and measuring spoons and cups along
with a funnel and lab safety gear to make toothpaste big enough to
use for brushing an elephant’s teeth.
But first, let us explain our used ingredients and their role in the
experiment:
 Hydrogen peroxide: is a colorless liquid acid (H2O2)
 Food coloring: used to make foam look even more like toothpaste.
 Liquid dish soap, used for forming foam.
 Yeast: used as a catalyst. A catalyst can be used to make a chemical
reaction happen faster.
 warm water used with yeast because it likes to live in warm
temperatures and will die in hot water and can’t reproduce in cold water.
3- The Procedure of the experiment:
a- We mix the yeast and warm water, and set it aside for 30
seconds to 1 minute
b- Then, we Pour the Hydrogen Peroxide into the bottle using a
funnel
c- Next, we mix soap and the Hydrogen Peroxide and food
coloring, but nothing happens at this point because none of
them is reactive with the other.
d- At the end, we pour the yeast mixture into the bottle and
moved back!
4- conclusion:
 When we added the activated yeast mixture to the container, it
immediately creates a foam that shoots out of the container.
 During this reaction, the hydrogen peroxide breaks down quickly
and split apart by the yeast. Hydrogen peroxide breaks down into
oxygen and water.

There is a lot of oxygen(gas) bubbles that needs to quickly push out
of the container.
 The soap added combines with water(liquid), and turns into foam.
 The oxygen (gas) gushing out is what makes the soap bubbles move
out of the container.
 Consequently, the foam that is pushed out of the bottle is warm to
the touch.
 The reaction occurs so fast that it also creates heat (energy) and
steam. This means our reaction is exothermic. An exothermic
reaction creates heat by shifting energy from the reaction to the
surrounding area.