Magnesium (Mg)

Silvery-white metal

Magnesium is a lightweight metal known for its bright white flame when burned, and it is essential for biological systems as the central atom in chlorophyll and drives over 300 enzymatic reactions. Its hexagonal close-packed crystal structure gives it a low density of 1.738 g/cm³.

Key metrics

Density1.74g/cm³

Melting point923K

Boiling point1,363K

Electronegativity1.31Pauling

Discovery

1755discovered

Discovered by: Joseph Black
Reactivity profile: Burns Brightly in Air
Reactivity: Medium
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Ne]}\; \textcolor{#ef4444}{3_{s}^{2}}

[Ne] 3s2

Wave function

\Psi_{\text{Mg}} \approx \frac{1}{\sqrt{12!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{12}(\mathbf{r}_{12}) \right|

Probability density $|\Psi|^2$ across the Mg valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 160 pm
Ionization energy: 738 kJ/mol
Electron affinity: 0 kJ/mol
Crystal structure: Hexagonal close-packed (hcp)

Oxidation states

Acid/base

Basic

Strongly acidicStrongly basic

State at 25 °CSolid

923 K1363 K298 K

Emission spectrum

4 transitions

380450500550600650700780

VioletBlueGreenYellowRed

383.8nmMg I (UV)UV50%

516.7nmMg IGreen85%

517.3nmMg IGreen90%

518.4nmMg I (green)Green100%

Dominant line 518.4 nmRange 384–518 nmTransitions 4