Osmium (Os)
Osmium (Os) is element 76 of the periodic table, a transition metal in period 6 and group 8. Its standard atomic weight is 190.23, so one mole of osmium atoms has a mass of 190.23 g. At room temperature it is a solid; it melts at 3032.85 °C and boils at 5011.85 °C.
| Atomic number | 76 |
|---|---|
| Symbol | Os |
| Standard atomic weight | 190.23 |
| Molar mass | 190.23 g/mol |
| Category | Transition metal |
| Group | 8 |
| Period | 6 |
| Block | d-block |
| Electron configuration | [Xe] 6s2 4f14 5d6 |
| Oxidation states | +4, +3 |
| Electronegativity (Pauling) | 2.2 |
| Atomic radius (van der Waals) | 216 pm |
| First ionisation energy | 8.7 eV (839.4 kJ/mol) |
| Electron affinity | 1.1 eV |
| State at room temperature | Solid |
| Melting point | 3306 K (3032.85 °C) |
| Boiling point | 5285 K (5011.85 °C) |
| Density | 22.57 g/cm³ |
| Discovered | 1803 |
Group 8
Calculate with Osmium
Atomic weight: IUPAC CIAAW standard atomic weight. Other properties: PubChem (U.S. National Library of Medicine, public domain). Values such as melting point and radius depend on how they were measured; check a data book for precise work.