Helium vs Molybdenum
| Property | He Helium | Mo Molybdenum |
|---|---|---|
| Atomic number | 2 | 42 |
| Symbol | He | Mo |
| Name | Helium | Molybdenum |
| Category | noble-gas | transition-metal |
| Standard Atomic Weight | 4.002602 u | 95.95 u |
| Period | 1 | 5 |
| Group | 18 | 6 |
| Block | s | s |
| Phase at STP | gas | solid |
| Electron configuration | 1s2 | [Kr]5s14d5 |
| Oxidation states | [0] | [-4, -2, -1, 0, 1, 2, 3, 4, 5, 6] |
| Electronegativity (Pauling) | N/A | 2.16 |
| Electron affinity | -0.5 eV | 0.744 eV |
| Density | 0.1785 kg/m³ | 1.020000e+4 kg/m³ |
| Melting point | -272.2 °C | 2622.85 °C |
| Boiling point | -268.93 °C | 4638.85 °C |
| Discovery year | 1868 | 1778 |