Aluminium (Al): Electron Configuration, Properties and Uses
Aluminium (Al): Electron Configuration, Properties and Uses
Electron configuration [Ne] 3s2 3p1 · group 13 · period 3 · Ar 26.982
Aluminium data
- Atomic number
- 13
- Relative atomic mass
- 26.982
- Group
- 13
- Period
- 3
- Block
- p
- Category
- Post-transition metal
- Electron configuration
- [Ne] 3s2 3p1
- Full configuration
- 1s2 2s2 2p6 3s2 3p1
- Electrons per shell
- 2, 8, 3 (K L M)
- Valence electrons
- 3
- Electronegativity (Pauling)
- 1.61
- First ionisation energy
- 5.986 eV
- Atomic radius (van der Waals)
- 184 pm
- State at room temperature
- Solid
- Melting point
- 660 °C
- Boiling point
- 2519 °C
- Density
- 2.7 g/cm³
- Common oxidation states
- +3
- Discovered
- ancient times
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 8 · M 3
Orbital diagram (outer electrons)
About aluminium
With atomic number 13, aluminium (Al) has 13 protons in its nucleus and 13 electrons as a neutral atom. It is a post-transition metal in group 13, period 3, p-block. Aluminium has been known and used since ancient times. Aluminium is a solid at room temperature, melting at 660 °C and boiling at 2519 °C.
Aluminium electron configuration
The electron configuration of aluminium is 1s2 2s2 2p6 3s2 3p1, or in short [Ne] 3s2 3p1. Its electrons occupy 3 shells: K = 2, L = 8, M = 3. Aluminium has 3 valence electrons in the M shell (3s2 3p1), which is why it sits in group 13. When it forms cations, electrons leave the outermost subshell first: Al3+ = [Ne] (like neon).
Filling order: 1s2(2) → 2s2(4) → 2p6(10) → 3s2(12) → 3p1(13)
Uses of aluminium
In industry and the laboratory, aluminium turns up in many places, for example cans and foil, aircraft and vehicle frames, power cables, and alum for water treatment. For research and analysis you can browse aluminium compounds in the AMI Scientific catalogue.
Safety
Solid aluminium is safe, but fine aluminium powder is flammable. Always read the safety data sheet (SDS) before working with a chemical.
Other elements in group 13
Frequently asked questions
What is the electron configuration of aluminium?
The electron configuration of aluminium (Al, atomic number 13) is 1s2 2s2 2p6 3s2 3p1, or [Ne] 3s2 3p1 in short. By shell: 2, 8, 3.
How many valence electrons does aluminium have?
Aluminium has 3 valence electrons.
Which group and period is aluminium in?
Aluminium is in group 13, period 3, p-block.
What is the atomic mass of aluminium?
The relative atomic mass of aluminium is 26.982. Use it to calculate molar mass with the molar mass calculator.
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