Helium vs Ruthenium
| Property | He Helium | Ru Ruthenium |
|---|---|---|
| Atomic number | 2 | 44 |
| Symbol | He | Ru |
| Name | Helium | Ruthenium |
| Category | noble-gas | transition-metal |
| Standard Atomic Weight | 4.002602 u | 101.07 u |
| Period | 1 | 5 |
| Group | 18 | 8 |
| Block | s | s |
| Phase at STP | gas | solid |
| Electron configuration | 1s2 | [Kr]5s14d7 |
| Oxidation states | [0] | [-4, -2, 1, 2, 3, 4, 5, 6, 7, 8] |
| Electronegativity (Pauling) | N/A | 2.2 |
| Electron affinity | -0.5 eV | 1.05 eV |
| Density | 0.1785 kg/m³ | 1.210000e+4 kg/m³ |
| Melting point | -272.2 °C | 2333.85 °C |
| Boiling point | -268.93 °C | 4149.85 °C |
| Discovery year | 1868 | 1828 |