Conversation so far:
What is chemical energy?
Chemical energy is the potential of a chemical substance to undergo a transformation through a chemical reaction to transform other chemical substances. Examples include batteries, food, gasoline, and etc.
Describe a chemical reaction.
No new atoms are created, and no atoms are destroyed. In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
How is a chemical reaction represented mathematically?
A chemical reaction may be represented by a chemical equation, which indicates the number and type of each atom, as well as their organization into molecules or ions. A chemical equation uses the element symbols as shorthand notation for the elements, with arrows to indicate the direction of the reaction.

Question: Give me an example.
Self-contained rewrite: Give me an example of a chemical reaction.