Atomic number 12
Magnesium
Alkaline earth metal
Quick facts
- Atomic mass
- 24.305
- Group
- 2
- Period
- 3
- State (STP)
- solid
- Electronegativity
- 1.31
- Common ox. states
- +2
Properties
Electron configuration
[Ne] 3s²
- Ionization energy
- 737.7 kJ/mol
- Electron affinity
- -40.0 kJ/mol
- Melting point
- 923.00 K (649.9 °C)
- Boiling point
- 1363.00 K (1089.8 °C)
How it bonds
Magnesium loses both 3s electrons to make Mg²⁺ — the stable, predictable +2 ion you see in MgO, MgCl₂, Mg(OH)₂, and inside every chlorophyll molecule. Burns brilliantly white in air, forming MgO (a textbook ionic oxide).
Where you meet it
- Periodic Quest challengeunlock card