Helium vs Nickel
| Property | He Helium | Ni Nickel |
|---|---|---|
| Atomic number | 2 | 28 |
| Symbol | He | Ni |
| Name | Helium | Nickel |
| Category | noble-gas | transition-metal |
| Standard Atomic Weight | 4.002602 u | 58.6934 u |
| Period | 1 | 4 |
| Group | 18 | 10 |
| Block | s | s |
| Phase at STP | gas | solid |
| Electron configuration | 1s2 | [Ar]4s23d8 |
| Oxidation states | [0] | [-2, -1, 0, 1, 2, 3, 4] |
| Electronegativity (Pauling) | N/A | 1.91 |
| Electron affinity | -0.5 eV | 1.156 eV |
| Density | 0.1785 kg/m³ | 8912 kg/m³ |
| Melting point | -272.2 °C | 1454.85 °C |
| Boiling point | -268.93 °C | 2912.85 °C |
| Discovery year | 1868 | 1751 |