Physics
Physics
Problem
For an approximate analysis, assume the binding energy per nucleon is for deuterium () and for helium-4 (). Calculate the energy released, in MeV, when two deuterium nuclei fuse to form one helium-4 nucleus.Intuitive explanation
Nuclear fusion releases energy because the products are more tightly bound than the reactants—they sit deeper in the binding energy well. Here, you're comparing the total binding energy before and after the reaction: multiply binding energy per nucleon by the mass number for each nucleus, then find the difference. That difference is the energy released, since the final state "gives back" more binding energy than the initial state required.
Intuitive explanation
Nuclear fusion releases energy because the products are more tightly bound than the reactants—they sit deeper in the binding energy well. Here, you're comparing the total binding energy before and after the reaction: multiply binding energy per nucleon by the mass number for each nucleus, then find the difference. That difference is the energy released, since the final state "gives back" more binding energy than the initial state required.