76190.23OsOsmium
Osmium (Os) — element 76transition metal · group 8, period 6
Osmium is a chemical element with the symbol Os and atomic number 76. It is a transition metal in group 8, period 6 of the periodic table (the d-block), with a standard atomic mass of 190.23 u. At room temperature (25 °C) osmium is a solid.
💡 Known for: The densest naturally occurring element; used in fountain-pen tips and electrical contacts.
# Osmium properties
| Symbol | Os |
|---|---|
| Atomic number | 76 |
| Atomic mass | 190.23 u |
| Category | transition metal |
| Group | 8 |
| Period | 6 |
| Block | d-block |
| Electron configuration | [Xe] 4f¹⁴ 5d⁶ 6s² |
| Full configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁶ 6s² |
| Electrons per shell | 2, 8, 18, 32, 14, 2 |
| Protons / electrons | 76 / 76 |
| State at 25 °C | solid |
| Melting point | 3306 K (3032.8 °C, 5491.1 °F) |
| Boiling point | 5285 K (5011.9 °C, 9053.3 °F) |
| Density | 22.59 g/cm³ |
| Electronegativity (Pauling) | 2.2 |
| First ionization energy | 8.438 eV |
| Atomic radius | 185 pm |
| Discovered | 1803 |
# Electron configuration of osmium
The electron configuration of osmium is [Xe] 4f¹⁴ 5d⁶ 6s², written out in full as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁶ 6s². Its 76 electrons fill 6 shells as 2, 8, 18, 32, 14, 2, so the outermost shell holds 2 electrons.
# Related elements
ReRheniumprevious elementIrIridiumnext elementFeIrongroup 8RuRutheniumgroup 8HsHassiumgroup 8ScScandiumtransition metalTiTitaniumtransition metalVVanadiumtransition metalCrChromiumtransition metalMnManganesetransition metalCoCobalttransition metalNiNickeltransition metalCuCoppertransition metal
# Osmium FAQ
What is the atomic number of osmium?
The atomic number of osmium is 76: every osmium atom has 76 protons in its nucleus. Its symbol is Os.
What is the atomic mass of osmium?
The standard atomic mass of osmium is 190.23 u.
What is the electron configuration of osmium?
Osmium's electron configuration is [Xe] 4f¹⁴ 5d⁶ 6s² (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁶ 6s²), with 2, 8, 18, 32, 14, 2 electrons per shell.
Is osmium a metal?
Yes. Osmium is a transition metal, one of the metals.
What is the melting point of osmium?
Osmium melts at 3306 K (3032.8 °C, 5491.1 °F) and boils at 5285 K (5011.9 °C, 9053.3 °F).
What is osmium used for / known for?
The densest naturally occurring element; used in fountain-pen tips and electrical contacts.