A formula equation is a visual representation of a reaction using chemical formulas. A chemical formula is an expression that states the number and types of atoms that make up any given molecule using the symbols for the elements and sub-scripted numbers.

The most well-known example of a chemical formula is water, which is H?O. Formula equations are used to keep larger and more complex equations and reactions as simple and short as possible. Furthermore, chemical formulas are standardized, so no matter where they are used, scientists know what they mean in any language. In a chemical formula equation, the reactants are listed on the left side of the equation and the result on the right.