The products of a chemical equation are C*O_{2} and 2H_{2} * O . Which set of atoms must make up the equation's reactants so that the equation models the law of conservation of mass?

The starting materials in a nuclear change have a total mass of 2.3465 x 10-27 kg. after the change, the resulting materials have a mass of 2.3148 x 10-27 kg. how much energy was released during the change? 2.85 x 10-12 2.08 * 10-10 j 0 211 * 10-10 j 8.56 * 10-43