Magnesium vs Selenium
| Property | Mg Magnesium | Se Selenium |
|---|---|---|
| Atomic number | 12 | 34 |
| Symbol | Mg | Se |
| Name | Magnesium | Selenium |
| Category | alkaline-earth-metal | nonmetal |
| Standard Atomic Weight | 24.3055 u | 78.971 u |
| Period | 3 | 4 |
| Group | 2 | 16 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [Ne]3s2 | [Ar]4s23d104p4 |
| Oxidation states | [0, 1, 2] | [-2, -1, 0, 1, 2, 3, 4, 5, 6] |
| Electronegativity (Pauling) | 1.31 | 2.55 |
| Electron affinity | -0.4 eV | 2.0206 eV |
| Density | 1740 kg/m³ | 4809 kg/m³ |
| Melting point | 649.85 °C | 220.5 °C |
| Boiling point | 1089.85 °C | 684.85 °C |
| Discovery year | 1755 | 1817 |