Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Monatomic ions are single atoms that have gained or lost electrons, resulting in a net electrical charge. They can be either positively charged (cations) or negatively charged (anions).
5 Must Know Facts For Your Next Test
Monatomic cations are typically formed by metal atoms losing one or more electrons.
Monatomic anions are usually formed by nonmetal atoms gaining one or more electrons.
The charge of a monatomic ion is indicated by a superscript number and sign after the element symbol, such as Na^+ or Cl^-.
Transition metals often form monatomic ions with multiple possible charges, like Fe^2+ and Fe^3+.
The stability of monatomic ions is influenced by the ionization energy for cations and electron affinity for anions.