The law of conservation of mass states that in a chemical reaction, mass is neither created nor destroyed. that means, the total mass for the reactants needed to equal the total mass of the products. the reactants for photosynthesis are 6 carbon dioxide, 6 water and sunlight. the mass of these reactants adds to equal the mass of the products, which are 1 glucose and 6 oxygen. there are equal amounts of each atom on both sides of the chemical equation. the law of conservation of energy states that energy cannot be created nor destroyed. this is a little more confusing because energy (sunlight) is a reactant in the equation and not a product, so it had to go somewhere. energy can be converted from one form to another. in the case of photosynthesis, energy is converted from sunlight into glucose. glucose is a carbohydrate which is a molecule that the body can break down for energy.