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Aluminium (Al)

Aluminium is a chemical element of the periodic table with chemical symbol Al and atomic number 13 with an atomic weight of 26.9815 u and is classed as post-transition metal and is part of group 13 (boron group). Aluminium is solid at room temperature.

Aluminium in the periodic table

Atomic number13
Group13 (Boron group)
ClassificationPost-Transition Metal
AppearanceSilvery gray metallic
Color Silver
Number of protons13 p+
Number of neutrons14 n0
Number of electrons13 e-
From Wikipedia, the free encyclopediaAluminium (or aluminum; see different endings) is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal. Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal, in the Earth's crust.

Physical properties

Phase at STPSolid
Density2.7 g/cm3
Atomic weight26.9815 u

Thermal properties

Melting point933.47 K
660.32 °C
1220.576 °F
Boiling point2743 K
2469.85 °C
4477.73 °F
Heat of vaporization290.8 kJ/mol

Atomic properties

Electronegativity (Pauling Scale)1.61
Electron affinity41.762 kJ/mol
Oxidation states−2, −1, +1, +2, +3
(an amphoteric oxide)
Ionization energies
  1. 577.5 kJ/mol
  2. 1816.7 kJ/mol
  3. 2744.8 kJ/mol
  4. 11577 kJ/mol
  5. 14842 kJ/mol
  6. 18379 kJ/mol
  7. 23326 kJ/mol
  8. 27465 kJ/mol
  9. 31853 kJ/mol
  10. 38473 kJ/mol
  11. 42647 kJ/mol
  12. 201266 kJ/mol
  13. 222316 kJ/mol

Electron configuration for aluminium

Electron configuration
Shorthand configuration
[Ne] 3s2 3p1
Electron configuration
Full configuration
1s2 2s2 2p6 3s2 3p1
Electron configuration chart
Electrons per shell2, 8, 3
Valence electrons 3
Valency electrons 3
Bohr model
AluminiumElectron shell for Aluminium, created by Injosoft ABAl
Figure: Shell diagram of Aluminium (Al) atom.
Orbital Diagram

The history of Aluminium

PredictionAntoine Lavoisier (1782)
DiscoveryHans Christian Ørsted (1824)
Named byHumphry Davy (1812)
Discovery of aluminium
Attempts to produce aluminium metal date back to 1760. The first successful attempt, however, was completed in 1824 by Danish physicist and chemist Hans Christian Ørsted. He reacted anhydrous aluminium chloride with potassium amalgam, yielding a lump of metal looking similar to tin. He presented his results and demonstrated a sample of the new metal in 1825. In 1827, German chemist Friedrich Wöhler repeated Ørsted's experiments but did not identify any aluminium. He conducted a similar experiment in the same year by mixing anhydrous aluminium chloride with potassium and produced a powder of aluminium. In 1845, he was able to produce small pieces of the metal and described some physical properties of this metal. For many years thereafter, Wöhler was credited as the discoverer of aluminium. The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856.


List of unique identifiers for Aluminium in various chemical registry databases
CAS Number7429-90-5
ChemSpider ID4514248
EC number231-072-3
PubChem CID Number5359268