Splitting up of heavy nucleus like uranium into lighter nuclei, when bombarded with sow neutron, with release of energy in the form of heat and light, that energy is called nuclear fission.
Combination of two or more lighter nuclei into a heavy nucleus with release of large amount of heat, and light is called nuclear fusion.
Nuclear fission, subdivision of a heavy atomic nucleus, such as that of uranium or plutonium, into two fragments of roughly equal mass. The process is accompanied by the release of a large amount of energy. Nuclear fission. In order to initiate most fission reactions, an atom is bombarded by a neutron to produce an unstable isotope, which undergoes fission.xample of Nuclear Fission
In nuclear power plants, energetic neutrons are directed into a sample of the isotope uranium-235. The energy from the neutrons can cause the uranium nucleus to break in any of a number of different ways. A common fission reaction produces barium-141 and krypton-92.
Nuclear fusion is what happens in the Sun and other stars and involves joining two atomic nuclei to make one larger one. Both reactions release large amounts of energy, but with nuclear fusion there is very high energy yield and very low nuclear waste production.Fusion requires temperatures of about 100 million Kelvin (approximately six times hotter than the sun's core). At these temperatures, hydrogen is a plasma, not a gas. Plasma is a high-energy state of matter in which all the electrons are stripped from atoms and move freely about.