Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
Anions are negatively charged ions formed when an atom gains one or more electrons. They play crucial roles in various biological and chemical processes.
AP course connection
Topic 2.1: 2.1 Atoms, Isotopes, Ions, and Molecules: The Building Blocks