Magnesium (Mg) is chemical element 12, an alkaline earth metal in group 2, period 3 (PubChem).
- Atomic number: 12
- Symbol: Mg
- Group: 2
- Period: 3
- Atomic mass: 24.305 u
- Electron configuration: [Ne]3s2
- Electronegativity (Pauling scale): 1.31
- Atomic radius (van der Waals): 173 pm
- Ionization energy: 7.646 eV
- Oxidation states: +2
- Standard state: Solid
- Melting point: 923 K
- Boiling point: 1363 K
- Density: 1.74 g/cm³
- Chemical group: Alkaline earth metal
- Year discovered: 1808