Aluminium
Aluminium (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.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
10 is the [Ne] core total across two shells.
At a glance
- Atomic number
- 13
- Atomic mass
- 26.981539 u
- Phase
- Solid
- Density
- 2.7 g/cm³
- Melting point
- 933.47 K
- Boiling point
- 2,743 K
- First ionization energy
- 577.5 kJ/mol
- Electronegativity
- 1.61
- Electron affinity
- 41.762 kJ/mol
- Molar heat capacity
- 24.2 J/(mol·K)
- Period
- 3
- Appearance
- silvery gray metallic
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.