Chemical Reactions

A chemical reaction can be expressed as a chemical equation. A chemical equation is a statement of a chemical change using symbols. Consider the reaction between carbon and oxygen gas to form carbon dioxide. The starting substances, known as reactants, are carbon and oxygen gas. The final substance formed, known as a product, is carbon dioxide. To write the chemical equation for a reaction, first you write the symbols for the reactants, then an arrow, followed by the symbols for the products. The “plus” (+) sign separates the reactants or products from one another. The arrow indicates the direction of the reaction or “to yield.”