Niobium vs Rhenium
| Property | Nb Niobium | Re Rhenium |
|---|---|---|
| Atomic number | 41 | 75 |
| Symbol | Nb | Re |
| Name | Niobium | Rhenium |
| Category | transition-metal | transition-metal |
| Standard Atomic Weight | 92.90637 u | 186.207 u |
| Period | 5 | 6 |
| Group | 5 | 7 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s14d4 | [Xe]6s24f145d5 |
| Oxidation states | [-3, -1, 0, 1, 2, 3, 4, 5] | [-3, -1, 0, 1, 2, 3, 4, 5, 6, 7] |
| Electronegativity (Pauling) | 1.6 | 1.9 |
| Electron affinity | 0.893 eV | 0.15 eV |
| Density | 8570 kg/m³ | 2.080000e+4 kg/m³ |
| Melting point | 2476.85 °C | 3185.85 °C |
| Boiling point | 4743.85 °C | 5595.85 °C |
| Discovery year | 1801 | 1925 |