Concept#note/concept
Nuclear energy leverages Einstein's law of conservation of energy (E=MC2) to harvest energy from lite atoms joined through Nuclear Fusion or heavy atoms split through Nuclear Fission. In both of these reactions the mass of the final product is slightly less than the mass of the initial atoms, and that lost mass is converted to energy.
Because MC2 is such a massive number, both processes produce a massive amount of energy. However, because Fusion joins lite atoms compared to heavy atoms in Fission the Fusion Reactions Produce Enormous Amounts of Energy from very little matter.