Osmium (Os)
[Xe] 4f¹⁴ 5d⁶ 6s². 4 unpaired electrons, period 6, group 8, d block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
OsOsmium, Z = 76, 190.23 u
[Xe] 4f14 5d6 6s2
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁶ 6s²
- Blockd block
- Period6
- Group8
- Valence8
- Unpaired4
- MagneticPara
Last electron 5d
- n5shell
- l2d subshell
- m−2orbital
- s−½spin down
Step by step
- Osmium has 76 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d⁶.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁶ 6s².
- Replace the xenon core with [Xe]: [Xe] 4f¹⁴ 5d⁶ 6s².
Osmium (Os): the numbers
| Atomic number | 76 |
|---|---|
| Atomic mass | 190.23 u |
| Period | 6 |
| Group | 8 |
| Block | d block |
| Valence electrons | 8 |
| Unpaired electrons | 4 |
| Magnetic | paramagnetic |
| Last electron | 5d: n = 5, l = 2, m = −2, s = −1/2 |
Osmium (Os): quick answers
What is the electronic configuration of osmium?
Osmium has 76 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁶ 6s², or [Xe] 4f¹⁴ 5d⁶ 6s² in short.
How many unpaired electrons does osmium have?
Osmium has 4 unpaired electrons, so it is paramagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of osmium?
The last electron goes into 5d: n = 5, l = 2, m = −2, s = −1/2. Orbitals fill from m = −l up, spin +½ first.