Nucleon (noun)

1. A particle, such as a proton or neutron, that forms the nucleus of an atom.
2. A subatomic particle that makes up the nucleus of an atom, either a proton or a neutron.

Origin:

From nucleus + -on.

Examples:

1. The number of nucleons in an atom determines its atomic number.
2. The nucleons in the nucleus are held together by the strong nuclear force.
3. The nucleons in heavy atoms are tightly packed together.
4. The number of protons and neutrons in a nucleus is known as the nucleon number.
5. The nucleon-nucleon interaction is the fundamental force that holds nuclei together.