Magnesium
alkaline earthProperties
| Property | Value |
|---|---|
| Atomic Mass | 24.305 amu |
| Category | alkaline earth |
| Group | 2 |
| Period | 3 |
| Electron Configuration | 1s2 2s2 2p6 3s2 |
| Electronegativity | 1.31 (Pauling) |
| Oxidation States | 2 |
| Melting Point | 923 K (649.9 °C) |
| Boiling Point | 1363 K (1089.8 °C) |
| Density | 1.738 g/cm³ |
| Discovered By | Joseph Black (1755) |
About Magnesium
Magnesium is the structural metal you reach for when every gram counts: density 1.738 g/cm³, about a third lighter than aluminum and roughly 75% lighter than steel, with enough strength once alloyed (typically with Al and Zn) to handle laptop chassis, camera bodies, and Formula 1 wheels. Crustal abundance sits around 2.3% by mass, and seawater carries Mg²⁺ at about 1.3 g/L (roughly 54 mmol/L) — that's where the Dow process pulls it from — electrolyzing molten MgCl₂ extracted from brine. The chemistry that made it famous is its combustion: Mg burns at over 3,000°C with an intense white light, hot enough to keep going by reducing CO₂ (so don't fight a Mg fire with a CO₂ extinguisher) and to crack water into hydrogen, which is why it needs Class D dry powder to suppress. In biology Mg²⁺ sits at the center of every chlorophyll molecule and acts as a cofactor in over 300 enzymes — including every kinase that runs on Mg-ATP rather than free ATP.
Fun Fact
During World War II, incendiary bombs made with magnesium were devastating because the metal burns at over 3,000 degrees Celsius and cannot be extinguished with water — dousing it with water actually feeds the fire by releasing hydrogen gas.
Common Uses
- Lightweight Mg-Al-Zn alloys for laptop chassis and automotive parts
- Central Mg²⁺ ion in chlorophyll, required for photosynthesis
- Pyrotechnics and emergency flares (white-light combustion)
- Mg-ATP cofactor in over 300 human enzymes
- Sacrificial anodes protecting buried steel pipelines and water heaters