How do nuclear changes demonstrate the Law of Conservation of Mass and Energy concerning fission and fusion?
Fission and fusion involve the conversion of mass into energy, the total of which is conserved according to E = mc^2. However, at the quantum scale, which is where nuclear reactions take place, it’s more accurate to view mass & energy as not two distinct concepts, but one, that of mass-energy. The “mass” of a nucleus is often slightly more than the total mass of it’s constituent nucleons, with the excess being in the form of potential mass-energy from the residual strong force locking the nucleons together. In a reaction like fission or fusion, excess mass-energy locked inside the nucleus is released as radiant and kinetic energy.
