Energy is produced when a heavy nucleus split into two nuclei or two nuclei combined to form a heavy nucleus. The reactions take place in the nucleus of an atom are called nuclear reactions. The main two nuclear reactions are fission reactions and fusion reactions.
When a fast moving neutron strikes on a heavy nucleus, nucleus splits into a product of nuclei, a product of neutrons and a large amount of energy. The targeting heavy nucleus is unstable so, when a neutron falls on it, it breaks into two or more nuclei. The new born nuclei are stable. This reaction is called nuclear fission reaction.
In fusion reaction two unstable nuclei are combined to form a heavy but stable nucleus. Energy is released during fusion reaction.
When a fast moving neutron strikes on a heavy nucleus, nucleus splits into a product of nuclei, a product of neutrons and a large amount of energy. The targeting heavy nucleus is unstable so, when a neutron falls on it, it breaks into two or more nuclei. The new born nuclei are stable. This reaction is called nuclear fission reaction.
In fusion reaction two unstable nuclei are combined to form a heavy but stable nucleus. Energy is released during fusion reaction.