Balanced equations Chemical equations must be balanced so that the quantities of reactants and products match. For an equation to be balanced there must be an equal numbers of atoms on each side.

The atoms in the reactants are: 1 calcium atom, 2 chlorine atoms, 2 sodium atoms, 2 hydrogen atoms, 2 carbon atoms, and 6 oxygen atoms The atoms in the products are: 1 calcium atom, 2 chlorine atoms, ...

The big number written in front of a molecule (coefficient) shows how many of that molecule there are. All the atoms in the products come from the atoms in the reactants. The reactants are on the left ...

A + sign separates two or more reactants or products. State symbols are used in symbol equations to show whether each chemical is a solid, liquid, gas or solution. But it’s often hard to know ...