Selenium vs Mercury
| Property | Se Selenium | Hg Mercury |
|---|---|---|
| Atomic number | 34 | 80 |
| Symbol | Se | Hg |
| Name | Selenium | Mercury |
| Category | nonmetal | transition-metal |
| Standard Atomic Weight | 78.971 u | 200.592 u |
| Period | 4 | 6 |
| Group | 16 | 12 |
| Block | p | s |
| Phase at STP | solid | liquid |
| Electron configuration | [Ar]4s23d104p4 | [Xe]6s24f145d10 |
| Oxidation states | [-2, -1, 0, 1, 2, 3, 4, 5, 6] | [-2, 1, 2] |
| Electronegativity (Pauling) | 2.55 | 2 |
| Electron affinity | 2.0206 eV | -0.5 eV |
| Density | 4809 kg/m³ | 1.353360e+4 kg/m³ |
| Melting point | 220.5 °C | -38.83 °C |
| Boiling point | 684.85 °C | 356.73 °C |
| Discovery year | 1817 | N/A |