A chemist mixes two liquids together. The reaction produces a gas and a solid. According to the law of conservation of mass, what should the chemist observe when she compares the total masses of the substances before and after the reaction? A.The masses are equal. B.The masses are inconsistent. C.The mass of the substances before the reaction is greater than the mass of the substances after the reaction. D.The mass of the substances before the reaction is less than the mass of the substances after the reaction.