Question

Distinguish between nuclear fusion and nuclear fission.

Answer 1

Hint: Nuclear fusion reaction takes place in the star because the core of the star is tremendously high.

Complete step by step answer:
Nuclear fusion: When two light nuclei are made to combine to form a heavy nucleus a large amount of energy is released is called nuclear fusion.
The process of combining two nuclei to form a heavy nucleus with the release of a large amount of energy is known as nuclear fusion.
When two light nuclei are combining to form a heavy nucleus, the mass of the product nucleus is slightly less than the sum of the masses of the light nuclei fusing together. As a result in nuclear fusion there is a mass difference. Because of this mass difference there is a release of a very large amount of energy according to the relation $E = \Delta m{c^2}$
Example: when two nuclei of heavy hydrogen ($H_1^2$ ) are combined,
${H^2} + H_1^2 \to H_1^3 + H_1^1 + 4.0{\text{MeV}}$
The nucleus of tritium $H_1^3$ so formed can again fuse with the deuterium nucleus,
$H_1^3 + H_1^2 \to He_2^4 + n_0^1 + 17.6MeV$
Energy released per fusion is less than the energy released per fission. The energy released per unit mass in nuclear fusion is greater than the energy released per unit mass in nuclear fission. The final products in nuclear fusion are not radioactive.
Nuclear fission: the process of splitting of a heavy nucleus into two nuclei of intermediate masses with the release of energy is nuclear fission.
A huge amount of energy is released. This is because the original mass of the nucleus is greater than the sum of the masses of the products produced after fission. This difference in the mass is converted into energy according to Einstein’ s equation, $E = \Delta m{c^2}$
Example: when a Uranium nucleus ($U_{92}^{235}$ ) is bombarded by a slow neutron (thermal neutron), the $U_{92}^{235}$ nucleus splits into two nuclei with a release of huge amount of energy.
\[U_{92}^{235} + n_0^1 \to \left[ {U_{92}^{236}} \right] \to Ba_{56}^{141} + Kr_{36}^{92} + 3n_0^1 + 200MeV\]
Apart from the energy in this process on an average two to three neutrons are also released. The released neutron can cause further nuclear fission reaction. The fission reaction is exothermic and fission products are radioactive.

Note: One of the day to day applications of the nuclear fission is the production of the electricity through the nuclear reactors. It is the advantageous method of producing the power.