Why is it difficult to accurately predict leads most common isotope?

Isotopes are the atoms of the same element with the difference in the number of neutrons. The number of electrons and protons are the same. The atomic masses are slightly different but the atomic number is the same. ... Therefore, it becomes difficult to exactly predict the common isotope of lead.

The atomic nucleus made up from protons (yellow) and neutrons (blue) and held together by nuclear forces. nuclear forces (also known as nuclear interactions or strong forces) are the forces that act between two or more nucleons. they bind protons and neutrons (“nucleons”) into atomic