Chemical equations represent, and are a summary of, chemical reactions.

Chemical equations are powerful and useful notations that can be used to quickly and concisely convey large amounts of information regarding chemical reactions.

Chemical reactions are composed of reactants (the initial substances that enter into the reaction) and products (the final substances that are present at the end of the reaction). Chemical equations are written with the reactants on the left side of the equation and with the reaction products on the right side of the equation. An arrow separates the reactants and products.

The arrow in a chemical equation represents the process of the chemical reaction. Because the chemical reaction can be simple or complex, the arrow can stand for a simple process or a complex reaction that involves many steps. Chemists often use other symbols in association with the arrow (above or below the...