Mrs. Smith wrote down a chemical equation on the board and stated that mass is conserved in the reaction. What did she mean? A. There are equal numbers of atoms on both the reactant side and the product sides.
B. The number of atoms on each side changes.
C. There are more atoms on the product side.
D, There are more atoms on the reaction side.

The correct answer is option A, that is, there is an equal number of atoms on both sides.
According to the law of conservation of mass, matter can neither be created nor be destroyed in the chemical reactions. In every chemical reaction, the similar mass of matter must end up in the products as initiated in the reactants.
The balanced chemical equations demonstrate that mass is conserved in chemical reactions. At the time of any chemical reaction, no particles are destroyed or created, that is, the atoms are basically arranged from the reactants to the products.