Arsenic Electron Configuration
Orbital diagram
- Valence electrons
- 5
- Unpaired electrons
- 3
- Block
- p-block
- Magnetism (atom)
- paramagnetic
Electrons per shell
| K (n = 1) | 2 |
|---|---|
| L (n = 2) | 8 |
| M (n = 3) | 18 |
| N (n = 4) | 5 |
Arsenic ion configurations
| Ion | Electrons | Configuration |
|---|---|---|
| As3− | 36 | [Ar] 3d10 4s2 4p6 |
How to write it
Place 33 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. Arsenic sits in period 4, group 15, 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 4p3.
Try arsenic and its ions in the calculator, or see the full arsenic data sheet.
Arsenic electron configuration FAQ
What is the electron configuration of arsenic?
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p³. Shorthand (noble gas) notation: [Ar] 3d¹⁰ 4s² 4p³.
What is the noble gas configuration of arsenic?
[Ar] 3d¹⁰ 4s² 4p³. The bracket stands for the Ar core electrons.
How many valence electrons does arsenic have?
5 (outer shell (n = 4)).
How many unpaired electrons does arsenic have?
3 in the ground state, following Hund’s rule. An atom with unpaired electrons is paramagnetic.
What is the electron configuration of As3−?
[Ar] 3d¹⁰ 4s² 4p⁶ (36 electrons).