The nuclear structures of the elements are formed by the mechanical interlocking of four particles of matter. These are Protons, Mesons, Neutrons, and Antineutrinos. The antineutrino is an internal structure within the neutron and is not shown in these mechanical diagrams of atomic nuclear structure. External electrons which mechanically attach to the mesons are also not shown. In these models, the protons, mesons, and neutrons, fit together like jigsaw puzzles and are held together mechanically somewhat like nuts and bolts. Metaphysical fields and forces such as the strong and weak forces are not assumed or needed in this explanation of nuclear physics. By following a few structural rules the most common and most stable nuclear isotope of each element is formed in a step by step process that also provides unique structural models of each of the 2000 or more radioactive isotopes that have been discovered.