The Law of Conservation of Mass states that during a chemical reaction, mass/matter is not Because of this law, there must be exactly the same number and kind of on each side of a chemical equation. To check if an enantion is balanced or not simply count the number of atoms of each element on the reactant side of the equation and check to see if there are the same number of atoms of each element on the ___side of the equation. If so, it is balanced.