Linked from
The 15 pages that link to Anion, each with the reason it gives.
Ionic bondingBroader topic: Anions provide the negative charges attracted to cations.
IonBroader topic: Electron gain leaves the ion with more electrons than protons.
IonizationBroader topic: Electron-attachment ionization produces anions.
Salt (chemistry)Broader topic: Anions provide the negative component that balances salt cations.