- A chemical equation in which the number of atoms of different elements on the reactants side (left side) are same as those on product side (right side) is called a balanced chemical equation.
- All the chemical equations must balance, because atoms are neither created nor destroyed in chemical reactions.
- The number of atoms of each element before and after reaction must be the same.
- According to the law of conservation of mass, the total mass of the substances that are taking part in a chemical reaction must be the same before and after the reaction.