The nucleus of an atom is located in a small volume at the center of an atom. The nucleus of Oxygen-16 is shown here.
Modern science asserts that the nucleus is composed of protons and neutrons.
Since protons strongly repel each other, the Strong Force was invented to hold the nucleus together. Unlike other forces, the Strong Force does not decrease with the square of distance between the objects of force. In the CSS model of the nucleus, a geometrical packing scheme for electrons and protons describes the shells of the nucleus. Quantum nuclear shell models cannot do this with so few assumptions. All rights reserved.