Aluminium (Al)
[Ne] 3s² 3p¹. 1 unpaired electron, period 3, group 13, p block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
AlAluminium, Z = 13, 26.982 u
[Ne] 3s2 3p1
In full: 1s² 2s² 2p⁶ 3s² 3p¹
- Blockp block
- Period3
- Group13
- Valence3
- Unpaired1
- MagneticPara
Last electron 3p
- n3shell
- l1p subshell
- m−1orbital
- s+½spin up
Step by step
- Aluminium has 13 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p¹.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p¹.
- Replace the neon core with [Ne]: [Ne] 3s² 3p¹.
Aluminium (Al): the numbers
| Atomic number | 13 |
|---|---|
| Atomic mass | 26.982 u |
| Period | 3 |
| Group | 13 |
| Block | p block |
| Valence electrons | 3 |
| Unpaired electrons | 1 |
| Magnetic | paramagnetic |
| Last electron | 3p: n = 3, l = 1, m = −1, s = +1/2 |
Aluminium (Al): quick answers
What is the electronic configuration of aluminium?
Aluminium has 13 electrons: 1s² 2s² 2p⁶ 3s² 3p¹, or [Ne] 3s² 3p¹ in short.
How many unpaired electrons does aluminium have?
Aluminium has 1 unpaired electron, so it is paramagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of aluminium?
The last electron goes into 3p: n = 3, l = 1, m = −1, s = +1/2. Orbitals fill from m = −l up, spin +½ first.