Question

why is a huge amount of energy released in nuclear reactions

Answer 1

because it is a exothermic reactions it liberate large amount of heat

Answer 2

in nuclear reactions there are basically two types of reactions first is the nuclear fission and then the second is the nuclear fusion. a nuclear fission heavy nucleus is split into two smaller nuclei with the release of huge amount of energy. secondly a nuclear fusion Two light nuclei of an atom are combined of used to form a heavy nucleus with the release of a tremendous amount of energy that is more than that of nuclear fission. both are used in generating electricity and making bombs of War. by nuclear fusion , hydrogen bomb is made and by nuclear fission, atom bomb is made.