Selenium Electron Configuration
Orbital diagram
- Valence electrons
- 6
- Unpaired electrons
- 2
- Block
- p-block
- Magnetism (atom)
- paramagnetic
Electrons per shell
| K (n = 1) | 2 |
|---|---|
| L (n = 2) | 8 |
| M (n = 3) | 18 |
| N (n = 4) | 6 |
Selenium ion configurations
| Ion | Electrons | Configuration |
|---|---|---|
| Se2− | 36 | [Ar] 3d10 4s2 4p6 |
How to write it
Place 34 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. Selenium sits in period 4, group 16, in the p-block, so its last electron enters a p subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [Ar] 3d10 4s2 4p4.
Try selenium and its ions in the calculator, or see the full selenium data sheet.
Selenium electron configuration FAQ
What is the electron configuration of selenium?
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁴. Shorthand (noble gas) notation: [Ar] 3d¹⁰ 4s² 4p⁴.
What is the noble gas configuration of selenium?
[Ar] 3d¹⁰ 4s² 4p⁴. The bracket stands for the Ar core electrons.
How many valence electrons does selenium have?
6 (outer shell (n = 4)).
How many unpaired electrons does selenium have?
2 in the ground state, following Hund’s rule. An atom with unpaired electrons is paramagnetic.
What is the electron configuration of Se2−?
[Ar] 3d¹⁰ 4s² 4p⁶ (36 electrons).