fusion and fission notes

It is  not only spontaneous disintegration  that characterized radioactive atoms, in fact even stable atoms can be made  to be radioactive , this is called artificial transmutation, this can be either fission or fusion.
Apart from alpha, beta or gamma particles other substances like neutron, positron can be emitted  and other substances that are not emitted in natural radioactive decay

Nuclear fusion
Nuclear fusion is the union of light nuclei to form a large nuclei under an extreme condition of heat and pressure. Nuclear fusion take place with a great lose of mass and  therefore large energy is released, nuclear fusion involve light nuclei coming together to forma heavier nuclei while nuclear fission involve a heavier nuclei splitting into a lighter nuclei. It  is an artificial transmutation and therefore intense eat and pressure are necessary.
Fusion take place in the sun and in the star, in the sun hydrogen nuclei fuse to form helium nuclei with a release of energy. This is how the sun produce it enormous  output of energy, by such fusion mass is gradually converted to energy .
Nuclear fusion on earth have not properly harness fusion reaction. Theoretically however fusion reaction offers a prospects of enormous quantity of cheap energy.
Nuclear fission
 it is the spitting of an atomic nuclei into two approximately equal  parts by bombardment of the nucleus with neutron. Nuclear fission may occur with an overall loss in mass, resultin gin the release of tremendous energy.
A good example of nuclear fission is the bombardment of uranium-235 with neutron, the result is the formation of another unstable  uranium isotope( compound nuclei in excited state) which quickly disintegrate  to yield the nuclei barium and krypton.
²³⁵U + ¹n = ²³⁶U
²³⁶U= ¹⁴¹Ba + ⁹²Kr + ¹n +¹n+ ¹n+ energy.
In this process mass is lost ,( the sum of mass of the product is less than the mass of the original substances and so energy is released. This means that mass has being converted to energy with asserted the conversion of mass to energy represented by the  the Einstein mass –energy equation  ∆e =∆mc²
Where ∆e is the energy release  in joules when a given mass ∆m  disintegrate in kg and c² is the speed of light. This type of energy is called nuclear energy, energy resulting from the destruction atomic nuclei.  Quantity of this energy reply on the mass destroyed. We started with only one neutron  from the reactant side and end up with more than one neutron. This means nuclear fission can keep itself going, the neutron produced can  be used to bombard more uranium  and we called it self-sustained chain reaction. Nuclear fission occurring under controlled conditions  provides atomic power which may be converted to electricity, this is the situation in many modern cities.