Question

Why is Iron 56 considered the most stable nucleus?

Answer 1

Isotopes:

Elements having the same atomic number but a different mass number, or in other words elements having the same number of protons but a different number of neutrons is termed Isotopes.

Iron has four isotopes, which are:

${}^{54}\mathrm{Fe}(5.84\%),{}^{56}\mathrm{Fe}(91.76\%),{}^{57}\mathrm{Fe}(2.12\%),\mathrm{and}{}^{58}\mathrm{Fe}(0.28\%)$

Stable nucleus condition:

• When the forces between the particles that make up the nucleus are balanced, a stable nucleus forms.
• When an atom has an excess of internal energy, i.e., an excess of protons or neutrons, it becomes unstable.
• The most common isotope of iron, iron-56, is thought to be the most stable nucleus since it has the lowest mass per nucleon of all nuclides.
• Iron-56 is also a strongly and effectively bound nucleus, having a binding energy of $8.8\mathrm{MeV}$per nucleon.
• Furthermore, it takes a significant amount of energy per nucleon to split the nucleus apart.