Iron-56

Iron-56, 56Fe
General
Symbol56Fe
Namesiron-56, 56Fe, Fe-56
Protons (Z)26
Neutrons (N)30
Nuclide data
Natural abundance91.754%
Isotope mass55.9349375(7) Da
Spin0+
Excess energy−60601.003±1.354 keV
Binding energy492253.892±1.356 keV
Isotopes of iron
Complete table of nuclides
Nuclear binding energy per nucleon of common isotopes; iron-56 labelled at the curve's crest. The rarer isotopes nickel-62 and iron-58, which both have higher binding energies, are not shown.

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

Of all nuclides, 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.[1]

The high nuclear binding energy for 56Fe represents the point where further nuclear reactions become energetically unfavorable. Because of this, it is among the heaviest elements formed in stellar nucleosynthesis reactions in massive stars. These reactions fuse lighter elements like magnesium, silicon, and sulfur to form heavier elements. Among the heavier elements formed is 56Ni, which subsequently decays to 56Co and then 56Fe.

  1. ^ Nuclear Binding Energy