About

Magnesium is a shiny gray solid and the eighth-most-abundant element in the Earth's crust. It is remarkably strong but lightweight, making it ideal for creating alloys used in cars, aircraft, and consumer electronics. It is also essential for all living cells, playing a central role in chlorophyll, the molecule that allows plants to perform photosynthesis. It burns with a brilliant white light.

Atomic Properties

Atomic Number12

Atomic Weight24.305 u

Neutrons (common)12

Electron Configuration[Ne] 3s²

Full Configuration1s² 2s² 2p⁶ 3s²

Electrons per Shell2, 8, 2

Electronegativity1.31

Electron Affinity-40 kJ/mol

Oxidation States+2

Covalent Radius130 pm

Van der Waals Radius173 pm

Ionic Radius72 pm

Periodic Table Position

Group2

Period3

BlockS

Chemical SeriesAlkaline earth metals

Physical Properties

State at STPsolid

Appearanceshiny grey solid

Crystal Structurehcp

Magnetic Orderingparamagnetic

Speed of Sound4,940 m/s

Poisson Ratio0.29

Thermal Properties

Melting Point923 K

Boiling Point1,363 K

Triple Point923 K

Thermal Expansion0 1/K

Thermal Conductivity156 W/(m·K)

Specific Heat1.023 J/(g·K)

Molar Heat24.869 J/(mol·K)

Heat of Fusion8.48 kJ/mol

Heat of Vaporization128 kJ/mol

Abundance

In Earth's Crust23,300 ppm

In Ocean1,290 ppm

In Solar System650 ppm

In Human Body270 ppm

In Universe590 ppm

Discovery

Discovered byJoseph Black & Humphry Davy

Discovery Year1,808

Occurrenceprimordial

CAS Number7439-95-4

Electron Configuration

Energy

↿⇂

Isotopes of Magnesium

Symbol ▲	Mass (u) ▲	Abundance ▲	Half-life ▲	Decay Mode ▲
²⁴Mg	23.985041	78.99%	Stable	Stable
²⁵Mg	24.985837	10%	Stable	Stable
²⁶Mg	25.982593	11.01%	Stable	Stable

Interactive Visualization

Explore the 3D Bohr model of Magnesium in our interactive viewer.

View 3D Model of Magnesium