Quick Facts
| Property | Value |
|---|---|
| Symbol | Os |
| Atomic Number | 76 |
| Atomic Mass | 190.23 u |
| Category | Transition Metal |
| Period | 6 |
| Group | 8 |
| Block | d |
| Electron Configuration | [Xe] 4f¹⁴ 5d⁶ 6s² |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 22.59 g/cm³ |
| Melting Point | 3033°C (3306 K) |
| Boiling Point | 5012°C (5285 K) |
| Appearance | Bluish-white, hard metal |
History and Discovery
Discovered by: Smithson Tennant Year of Discovery: 1803 Location: London, England
Etymology
Named from Greek "osme" meaning "smell," due to the pungent odor of osmium tetroxide.
Applications and Uses
- Fountain pen tips (osmium alloys)
- Electrical contacts
- Fingerprint detection (osmium tetroxide)
- Instrument pivots
- Staining for electron microscopy
Interesting Facts
- Densest naturally occurring element
- Osmium tetroxide is highly toxic and smells terrible
- Extremely rare and expensive
- Hardest of the platinum group metals
- Used in the very tips of high-quality fountain pens