Phosphorus vs Selenium
| Property | P Phosphorus | Se Selenium |
|---|---|---|
| Atomic number | 15 | 34 |
| Symbol | P | Se |
| Name | Phosphorus | Selenium |
| Category | nonmetal | nonmetal |
| Standard Atomic Weight | 30.973762 u | 78.971 u |
| Period | 3 | 4 |
| Group | 15 | 16 |
| Block | p | p |
| Phase at STP | solid | solid |
| Electron configuration | [Ne]3s23p3 | [Ar]4s23d104p4 |
| Oxidation states | [-3, -2, -1, 0, 1, 2, 3, 4, 5] | [-2, -1, 0, 1, 2, 3, 4, 5, 6] |
| Electronegativity (Pauling) | 2.19 | 2.55 |
| Electron affinity | 0.7466 eV | 2.0206 eV |
| Density | 1820 kg/m³ | 4809 kg/m³ |
| Melting point | 44.15 °C | 220.5 °C |
| Boiling point | 280.5 °C | 684.85 °C |
| Discovery year | 1669 | 1817 |