The atomic nucleus is the core of an atom (the basic units that make up all matter). Each atom is made up of a nucleus and a number of orbiting electrons. The nucleus is found at the center of an atom. It is composed of particles called protons, which are positively charged, and neutrons, which have no charge. Therefore the nucleus always has a positive charge. A neutron and a proton are jointly called a nucleon.
- ↑ Conoley, Chris; Hills, Phil (2008). Chemistry (3rd ed.). London: HarperCollins Publishers. p. 32. ISBN 978-0-00-726748-4.