Os
Osmium is the densest naturally occurring element at 22.587 g/cm3.
Physical Properties
| Atomic Mass | 190.23 u |
| Density | 22.587 g/cm³ |
| Melting Point | 3306.0 K |
| Boiling Point | 5285.0 K |
| Appearance | Silvery, blue cast metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 2.2 (Pauling) |
| 1st Ionization Energy | 840.0 kJ/mol |
| Electron Affinity | 103.99 kJ/mol |
| Oxidation States | +2, +3, +4, +6, +8 |
Atomic Properties
| Electron Configuration | [Xe] 4f14 5d6 6s2 |
| Atomic Radius | 135.0 pm |
| Covalent Radius | 144.0 pm |
| Van der Waals Radius | 216.0 pm |
Discovery
| Discovered By | Smithson Tennant |
| Discovery Year | 1803 |
| Location | London, England |
| Named After | Greek 'osme' meaning smell, from the pungent osmium tetroxide |
About Osmium
Osmium is a hard, brittle, bluish-white metal. Osmium tetroxide is highly toxic with a strong smell. The metal is extremely hard and corrosion-resistant.
Uses & Applications
Fountain pen nibs, electrical contacts, instrument pivots, and catalyst (osmium tetroxide).
Fun Fact
Osmium is the densest element, about twice as dense as lead. A cubic foot would weigh over 1,400 pounds.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 189 | 0.1615% | - | Yes |
| 190 | 0.2626% | - | Yes |
| 192 | 0.4078% | - | Yes |
Electron Configuration
[Xe] 4f14 5d6 6s2