Nuclear Fusion
    
    Nuclear Fusion
 Nuclear energy can also be released by fusion of two light elements  (elements with low atomic numbers). The power that fuels the sun and  the stars is nuclear fusion. In a hydrogen bomb, two isotopes of  hydrogen, deuterium and tritium are fused to form a nucleus of helium  and a neutron. This fusion releases 17.6 MeV of energy. Unlike nuclear  fission, there is no limit on the amount of the fusion that can occur.