Aluminium
Element 13 · Post-Transition Metal
Aluminium was once more precious than gold — Napoleon dined with aluminium cutlery while lesser guests used gold — until the Hall-Heroult process made it cheap in 1886. Today it is the most widely used non-iron metal on Earth. It is one-third the weight of steel, shrugs off corrosion behind a self-healing oxide skin, and conducts electricity well enough to string across continents as power lines. About 8 percent of Earth's crust is aluminium, locked in bauxite ore. Nearly 75 percent of all aluminium ever made is still in use, thanks to recycling that saves 95 percent of the smelting energy.
Key facts
| Atomic number | 13 |
|---|---|
| Atomic weight | 26.982 |
| Category | Post-Transition Metal |
| Group / Period | 13 / 3 |
| Block | p |
| Electron configuration | 1s2 2s2 2p6 3s2 3p1 |
| Common oxidation states | +3 |
| State at STP | Solid |
| Electronegativity | 1.61 |
| Atomic radius | 118 pm |
| Density | 2.70 g/cm³ |
| Melting point | 660.32 °C |
| Boiling point | 2519 °C |
Occurrence
Aluminium is the third most abundant element in Earth's crust, mined as bauxite ore in tropical regions. It never occurs as pure metal in nature — only in compounds.
Applications
Aircraft and vehicle bodies
Beverage cans and foil
Overhead power lines
Window frames and construction
Recyclable food packaging
Common compounds
- Aluminium oxide (Al2O3)
- Aluminium hydroxide (Al(OH)3)
- Cryolite (Na3AlF6)
- Bauxite (ore mixture)
Recycling one aluminium can saves enough energy to run a television for three hours — and the metal loses none of its quality.
Data source: IUPAC standard atomic weights 2021