Atomic number 12
Magnesium
Alkaline earth metal
In the real world
Quick facts
- Atomic mass
- 24.305
- Group
- 2
- Period
- 3
- State (STP)
- solid
- Electronegativity
- 1.31
- Common ox. states
- +2
Properties
[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 dangerous is it?
A light, useful metal that is safe as a solid block, but as ribbon or powder it burns with a blinding white flame.
- FlammableImmediate
Thin ribbon or fine powder ignites easily and burns at a very high temperature with intense white light. (a solid bar is hard to light, while ribbon and powder catch fire readily)
Kept away from flames and sparks and burned only in small, controlled amounts during a lab demo.
- ReactiveImmediate
Once it is burning it keeps going on its own and reacts even with water and carbon dioxide.
Never doused with water, which feeds the fire; it is smothered with a class-D dry extinguisher or dry sand.
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
