key term - Atomic Mass

Definition

The atomic mass is the total weight of protons, neutrons, and electrons in a single atom when at rest.

Related terms

Proton:

A subatomic particle with a positive charge that resides in an atom's nucleus.

Neutron: A subatomic particle with no charge (neutral) that also resides in an atom's nucleus.

Electron:

A subatomic particle with a negative charge that orbits around the nucleus of an atom.