Nucleons

Definition

Nucleons are the collective term for the protons and neutrons in an atomic nucleus. They are responsible for nearly all of the mass of the atom.

5 Must Know Facts For Your Next Test

1. Nucleons are bound together in the nucleus by the strong nuclear force.
2. The number of protons (one type of nucleon) defines the element, while the number of neutrons (another type) can vary among isotopes of that element.
3. Protons have a positive charge, while neutrons are electrically neutral.
4. The sum of protons and neutrons in a nucleus is called the mass number or nucleon number.
5. A change in the number of nucleons can result from nuclear reactions such as fission, fusion, or radioactive decay.

Review Questions

Related terms

Proton:

A positively charged particle found within atomic nuclei.

Neutron:

An electrically neutral particle found within atomic nuclei.

Strong Nuclear Force:

The force that holds protons and neutrons together in an atomic nucleus.