About

Aluminum is a silvery-white, lightweight, and non-magnetic metal. It is not found free in nature but is the most abundant metal in the Earth's crust. Its excellent resistance to corrosion, due to a passivating oxide layer, and its low density make it a vital material for transportation (aircraft, automobiles), packaging (cans, foil), and construction (window frames).

Atomic Properties

Atomic Number13

Atomic Weight26.982 u

Neutrons (common)14

Electron Configuration[Ne] 3s² 3p¹

Full Configuration1s² 2s² 2p⁶ 3s² 3p¹

Electrons per Shell2, 8, 3

Electronegativity1.61

Electron Affinity42.5 kJ/mol

Oxidation States+3

Covalent Radius121 pm

Van der Waals Radius184 pm

Ionic Radius53.5 pm

Periodic Table Position

Group13

Period3

BlockP

Chemical SeriesPost-transition metals

Physical Properties

State at STPsolid

Appearancesoft, ductile, silvery-white metal

Crystal Structurefcc

Magnetic Orderingparamagnetic

Speed of Sound5,100 m/s

Poisson Ratio0.35

Thermal Properties

Melting Point933.47 K

Boiling Point2,792 K

Triple Point933.473 K

Thermal Expansion0 1/K

Thermal Conductivity237 W/(m·K)

Specific Heat0.897 J/(g·K)

Molar Heat24.2 J/(mol·K)

Heat of Fusion10.71 kJ/mol

Heat of Vaporization294 kJ/mol

Abundance

In Earth's Crust82,300 ppm

In Ocean0.002 ppm

In Solar System80 ppm

In Human Body0.9 ppm

In Universe50 ppm

Discovery

Discovered byHans Christian Ørsted

Discovery Year1,825

Occurrenceprimordial

CAS Number7429-90-5

Electron Configuration

Energy

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Isotopes of Aluminum

Symbol ▲	Mass (u) ▲	Abundance ▲	Half-life ▲	Decay Mode ▲
²⁶Al	25.986891	Trace	717 ky	Positron Emission, Electron Capture
²⁷Al	26.981538	100%	Stable	Stable

Interactive Visualization

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

View 3D Model of Aluminum