Nuclear reaction takes place in the atomic nucleus only so t hat electron does not play any role in these reaction.
The result of nuclear reaction are the constructive or destructive changes in the nucleus. Such reaction are only possible in the nuclear reactors.
a) Fission Reaction
b) Fusion reaction
What is nuclear Fission Reaction :
The process of spontaneous decomposition of a heavy nucleus in to fragment of lighter nuclei is called ” nuclear Fission”
Nuclear fission can be brought about by bombarding the positively charged nuclei of certain isotopes of high mass number such as 135U , 238U or 237Pu by neutrons when the have nucleus splits in two lighter elements called ” fission fragments” accompanied by liberation of 2 or 3 fresh neutrons and energy.
The energy released by uranium during fission is 200 Me V. The neutrons emitted are very fast, which hit other uranium nuclei and produce fission. Such a fission can be brought about by neutrons of high, moderate or low speeds without being repulsed.
What is nuclear Fusion reaction :
The process in which two or more light nuclei fuse to give a heavier nucleus id called nucleus fusion.
The combination of two or more of the lightest nuclei by a process of fusion should, like fission, result in liberation of energy.
The energy released in nuclear fusion is larger than that released in fission. Where deuterium and tritium nuclei are brought together, they from a helium nucleus, with the release of a large amount of energy and a neutron. This process can be represented by the nuclear reactions.
In this process the sum of masses of the helium nucleus and the neutron is less than the sum of masses of the deuterium and tritium nuclei. This difference in mass according to Einstein’s mass energy relation released as energy, given by Δme2.