Iron-56

Stable_Isotope| isotope_name = Iron-56
isotope_filename =
alternate_names = Iron-56
mass_number = 56
symbol = Fe
num_neutrons = 30
num_protons = 26
abundance = 91.754%
mass = 55.9349375(7)
spin = 0+
excess_energy = -60601.003
error1 = 1.354
binding_energy = 492253.892
error2 = 1.356

Iron-56 is the most common isotope of iron. About 91.754% of all iron is iron-56.

Of all isotopes, iron-56 has the lowest mass per nucleon. With 8.8 MeV binding energy per nucleon, iron-56 is one of the most tightly bound nuclei. [ [http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html#c2 Nuclear Binding Energy] ] (Nickel-62 has a higher binding energy per nucleon; this is consistent with having a higher mass per nucleon because nickel-62 has a greater proportion of neutrons.) Thus, light elements undergoing nuclear fusion and heavy elements undergoing nuclear fission release energy as their nucleons bind more tightly, and the resulting nuclei approach the minimum total energy per nucleon, which occurs at iron-56. As the universe ages, more of the matter is converted into extremely tightly bound nuclei, such as iron-56. This progression of matter toward iron and nickel is one of the phenomena responsible for the heat death of the universe.

Isotope|element=iron
lighter=Iron-55
heavier=Iron-57
before=Manganese-56
Cobalt-56
after=Stable

References