Magnesium Electron Configuration
Magnesium (Mg) · 12 electrons · Alkaline earth metal
1s2 2s2 2p6 3s2
Noble gas notation: [Ne] 3s2
Orbital diagram
↑↓
1s↑↓
2s↑↓↑↓↑↓
2p↑↓
3s- Valence electrons
- 2
- Unpaired electrons
- 0
- Block
- s-block
- Magnetism (atom)
- diamagnetic
Electrons per shell
| K (n = 1) | 2 |
|---|---|
| L (n = 2) | 8 |
| M (n = 3) | 2 |
Magnesium ion configurations
| Ion | Electrons | Configuration |
|---|---|---|
| Mg2+ | 10 | [He] 2s2 2p6 |
How to write it
Place 12 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. Magnesium sits in period 3, group 2, in the s-block, so its last electron enters an s subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [Ne] 3s2.
Try magnesium and its ions in the calculator, or see the full magnesium data sheet.
Magnesium electron configuration FAQ
What is the electron configuration of magnesium?
1s² 2s² 2p⁶ 3s². Shorthand (noble gas) notation: [Ne] 3s².
What is the noble gas configuration of magnesium?
[Ne] 3s². The bracket stands for the Ne core electrons.
How many valence electrons does magnesium have?
2 (outer shell (n = 3)).
How many unpaired electrons does magnesium have?
0 in the ground state, following Hund’s rule. With all electrons paired, the atom is diamagnetic.
What is the electron configuration of Mg2+?
[He] 2s² 2p⁶ (10 electrons).