How do nuclear changes demonstrate the Law of Conservation of Energy?
Because energy is always conserved in nuclear reactions. The energy comes from the binding energy of the nucleons, which, from the outside, looks like ‘mass’. If you add up the masses of your initial nucleus/nuclei and compare it with the final nucleus/nuclei, you’ll see there’s a difference. Convert this to energy using E=mc^2, and there’s a source or sink of energy in your nuclear reaction (fusion up to iron from less massive nuclei, and fission down to iron from more massive nuclei release energy.
