Selenium vs Osmium
| Property | Se Selenium | Os Osmium |
|---|---|---|
| Atomic number | 34 | 76 |
| Symbol | Se | Os |
| Name | Selenium | Osmium |
| Category | nonmetal | transition-metal |
| Standard Atomic Weight | 78.971 u | 190.23 u |
| Period | 4 | 6 |
| Group | 16 | 8 |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s23d104p4 | [Xe]6s24f145d6 |
| Oxidation states | [-2, -1, 0, 1, 2, 3, 4, 5, 6] | [-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8] |
| Electronegativity (Pauling) | 2.55 | 2.2 |
| Electron affinity | 2.0206 eV | 1.1 eV |
| Density | 4809 kg/m³ | 2.258720e+4 kg/m³ |
| Melting point | 220.5 °C | 3032.85 °C |
| Boiling point | 684.85 °C | 5011.85 °C |
| Discovery year | 1817 | 1803 |