Rubidium Electron Configuration
Rubidium (Rb) · 37 electrons · Alkali metal
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1
Noble gas notation: [Kr] 5s1
Orbital diagram
↑↓
1s↑↓
2s↑↓↑↓↑↓
2p↑↓
3s↑↓↑↓↑↓
3p↑↓↑↓↑↓↑↓↑↓
3d↑↓
4s↑↓↑↓↑↓
4p↑
5s- Valence electrons
- 1
- Unpaired electrons
- 1
- Block
- s-block
- Magnetism (atom)
- paramagnetic
Electrons per shell
| K (n = 1) | 2 |
|---|---|
| L (n = 2) | 8 |
| M (n = 3) | 18 |
| N (n = 4) | 8 |
| O (n = 5) | 1 |
Rubidium ion configurations
| Ion | Electrons | Configuration |
|---|---|---|
| Rb+ | 36 | [Ar] 3d10 4s2 4p6 |
How to write it
Place 37 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. Rubidium sits in period 5, group 1, in the s-block, so its last electron enters an s subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [Kr] 5s1.
Try rubidium and its ions in the calculator, or see the full rubidium data sheet.
Rubidium electron configuration FAQ
What is the electron configuration of rubidium?
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s¹. Shorthand (noble gas) notation: [Kr] 5s¹.
What is the noble gas configuration of rubidium?
[Kr] 5s¹. The bracket stands for the Kr core electrons.
How many valence electrons does rubidium have?
1 (outer shell (n = 5)).
How many unpaired electrons does rubidium have?
1 in the ground state, following Hund’s rule. An atom with unpaired electrons is paramagnetic.
What is the electron configuration of Rb+?
[Ar] 3d¹⁰ 4s² 4p⁶ (36 electrons).