Helium vs Rutherfordium
| Property | He Helium | Rf Rutherfordium |
|---|---|---|
| Atomic number | 2 | 104 |
| Symbol | He | Rf |
| Name | Helium | Rutherfordium |
| Category | noble-gas | transition-metal |
| Standard Atomic Weight | 4.002602 u | 263 u |
| Period | 1 | 7 |
| Group | 18 | 4 |
| Block | s | s |
| Phase at STP | gas | solid |
| Electron configuration | 1s2 | [Rn]7s25f146d2 |
| Oxidation states | [0] | [3, 4] |
| Electronegativity (Pauling) | N/A | N/A |
| Electron affinity | -0.5 eV | 0.65 eV |
| Density | 0.1785 kg/m³ | 2.330000e+4 kg/m³ |
| Melting point | -272.2 °C | 2126.85 °C |
| Boiling point | -268.93 °C | 5526.85 °C |
| Discovery year | 1868 | 1964 |