Aluminium ion
Charge: 3+ · Type: Cation · Molar mass: 26.982 g/mol
Made of: aluminium
How it forms
Aluminium has three valence electrons. Losing all three gives Al3+ the electron arrangement of neon. The ion's high charge density makes aluminium salts hydrolyze in water, producing slightly acidic solutions.
Naming note
Al3+ is the aluminium ion (spelled aluminum in American usage). Aluminium has no other common ion, so no Roman numeral appears in the name.
Examples in compounds
Aluminium oxide
Aluminium sulfate
Aluminium chloride