decrease. Fusion, two atomic nuclei fuse together to form a heavier nucleus Fission, the breaking of a heavy nucleus into two (or more rarely three) lighter nuclei, and some neutrons The energy producing nuclear interaction of light elements requires some clarification. Frequently, all light element energy-producing nuclear interactions are classified as fusion, however by the given definition above fusion requires that the products include a nucleus that is heavier than the reactants. Light elements can experience energy producing nuclear interactions by fusion or fission. All energy producing nuclear interactions between two Hydrogen isotopes and between hydrogen and helium-3 are fusion as the product of these interactions include a heavier nucleus. However, the energy producing nuclear interaction of a neutron with Lithium–6 produces Hydrogen-3 and Helium-4, each a lighter nucleus. By the definition above, this nuclear interaction is fission, not fusion. When fission is caused by a neutron, as in this case, it is called induced fission. Light element energy-producing nuclear interactions:Fusion1H + 1H → 2He Q ≈ 1.44 MeV 1H + 2H → 3He Q ≈ 5.52 MeV 2H + 2H → 3H + p+ Q ≈ 4.08 MeV 2H + 2H → 3He + n Q ≈ 3.27 MeV 2H + 3H → 4He + n Q ≈ 17.53 MeV 2H + 3He → 4He + p+ Q ≈ 18.34 MeV 3He + 3He → 4He + p+ + p+ Q ≈ 12.85 MeV 3He + 6Li → 4He + 4He + p+ Q ≈ 22.36 MeVFission'6Li + p+ → 4He + 3He Q ≈ 4.02 MeV 6Li + 2H → 4He + 4He Q ≈ 11.18 MeV 6Li + 3He → 4He + 4He + p+ Q ≈ 0.94 MeV 7Li + p+ → 4He + 4He Q ≈ 17.34 MeV 7Li + 2H → 4He + 4He + n Q ≈ 15.11 MeV 11B + p+ → 4He + 4He + 4He Q ≈ 8.68 MeV Binding energy for atoms The binding energy of an atom (including its electrons) is not exactly the same as the binding energy of the atom's nucleus. The measured mass deficits of isotopes are always listed as mass deficits of the neutral atoms of that isotope, and mostly in . As a consequence, the listed mass deficits are not a measure of the stability or binding energy of isolated nuclei, but for the whole atoms. There is a very practical reason for