Physics – 5.1.1 The atom | e-Consult

A positively charged ion (cation) is formed when an atom loses one or more electrons. Atoms have a positive nucleus containing protons and a negative charge due to orbiting electrons. The number of protons in the nucleus defines the element. When an atom loses electrons, it has more protons than electrons, resulting in a net positive charge. The atom has become a cation. The number of electrons lost determines the charge of the ion. For example, if an atom loses one electron, it becomes a +1 ion (cation); if it loses two electrons, it becomes a +2 ion, and so on.

Diagram:

[Image missing: Ion Formation Diagram]