Aluminum Electron Configuration
Aluminum (Al) · 13 electrons · Post-transition metal
1s2 2s2 2p6 3s2 3p1
Noble gas notation: [Ne] 3s2 3p1
Orbital diagram
↑↓
1s↑↓
2s↑↓↑↓↑↓
2p↑↓
3s↑
3p- Valence electrons
- 3
- Unpaired electrons
- 1
- Block
- p-block
- Magnetism (atom)
- paramagnetic
Electrons per shell
| K (n = 1) | 2 |
|---|---|
| L (n = 2) | 8 |
| M (n = 3) | 3 |
Aluminum ion configurations
| Ion | Electrons | Configuration |
|---|---|---|
| Al3+ | 10 | [He] 2s2 2p6 |
How to write it
Place 13 electrons into subshells in the Aufbau order (1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p), filling s with 2, p with 6, d with 10 and f with 14. Aluminum sits in period 3, group 13, in the p-block, so its last electron enters a p subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [Ne] 3s2 3p1.
Try aluminum and its ions in the calculator, or see the full aluminum data sheet.
Aluminum electron configuration FAQ
What is the electron configuration of aluminum?
1s² 2s² 2p⁶ 3s² 3p¹. Shorthand (noble gas) notation: [Ne] 3s² 3p¹.
What is the noble gas configuration of aluminum?
[Ne] 3s² 3p¹. The bracket stands for the Ne core electrons.
How many valence electrons does aluminum have?
3 (outer shell (n = 3)).
How many unpaired electrons does aluminum have?
1 in the ground state, following Hund’s rule. An atom with unpaired electrons is paramagnetic.
What is the electron configuration of Al3+?
[He] 2s² 2p⁶ (10 electrons).