What is the difference between a chemical reaction and the chemical equation? These terms are often used interchangeably, but although they're related, they're different things. A chemical reaction is a process that occurs when one or more substances are changed into one or more new substances. For example:

Hydrogen and oxygen gas combine to produce water.

Sodium chloride (table salt) dissociates in water to form sodium and chlorine ions.

Methane combusts in oxygen to form carbon dioxide, heat, and water.

On the other hand, a chemical equation is the symbolic representation of a chemical reaction. Atomic symbols are used to represent the elements that take part in a reaction. The numbers represent the ratios of reactants and products that produce the reaction. Arrows point the direction a reaction occurs, with the arrow pointing from reactants to products. For example, using for the above chemical reactions:

To review:

Chemical reactions are processes in which reactants become new products.

Chemical equations are the symbolic representation of chemical reactions.