An amount of energy released during fusion and fission reactions is known as nuclear energy. When a heavy nucleus breaks into two nuclei and products of neutrons, energy is released, this energy is called nuclear energy. This process is called fission reaction. In fission reaction when a neutron falls on a nucleus, a heavy nucleus is formed which is unstable. In fusion reactions two nuclei are combined to form a heavy nucleus. This nucleus is more stable than the two nuclei. In the formation of this heavy nucleus an amount of energy is released, this energy is also a form of nuclear energy. The amount of the nuclear energy can be calculated by Einstein mass-energy equation. The formula for energy is delE=del m c2 ( 'del E' is the amount of energy released, 'del m' is the mass defect and c is the speed of light).
