Fission is a process in which a nucleus splits into two parts that are roughly the same size of the original nucleus. In fusion, two nuclei fuse, or combine, to form one nucleus. These reactions seem to be opposite to each other and yet both release large amounts of energy. Explain why this is not a contradiction. Use the graph of binding energy per nucleon in your answer. That's what I got The energy is released as the products move closer to iron on the binding energy graph. This is as iron is the most stable nuclei. Hydrogen is on the left and the produced helium is closer to iron so it releases energy. Uranium is way on the right and the products are closer to iron so energy is released. This increase in stability is what causes energy to be released; this is pretty much the case for chemical reactions as well... Most small stars die after iron has been produced in the core as it is not able to produce any more energy by fusing iron nuclei. Huge stars can fuse these nuclei but this is because they have so much energy and energy is actually used up in making heavier elements. IS THAT RIGHT?