Chemical reactions are an important part of life. This is the mechanism by which elements are transformed into compounds, and other more complex particles. Chemical reactions usually occur between substances that are referred to as chemical reactants. These chemical reactants undergo changes that results in the formation of a new substance, called the product. At the end of the chemical reaction, reactants are usually consumed and are transformed into a new substance. On the other hand, products are end points of chemical reactions, and they are produced at the end of the process. In a chemical equation, reactants are commonly placed on the right side of the arrow. In contrast, chemical products are placed on the left side of the equation.