Answer:
Nuclear fusion can be defined asva reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manifested as either the release or absorption of energy . This difference in mass arises due to the difference in atomic " binding energy " between the atomic nuclei before and after the reaction. Fusion is the process that powers active or " main sequence " stars , or other high magnitude stars.
A fusion process that produces nuclei lighter than iron-56 or nickel-62 will generally release energy. These elements have relatively small mass per nucleon and large binding energy per
nucleon . Fusion nuclei lighter than these releases energy (an exothermic process), while fusion of heavier nuclei results in energy retained by the product nucleons, and the resulting reaction is endothermic .
Nuclear fusion generates electricity (as a proposed form of power) by using heat from nuclear fusion reactions. In a fusion process, two lighter atomic nuclei combine to form a heavier nucleus, while releasing energy. The devices designed to harness this energy are known as fusion reactors.