Niobium (Nb)
Niobium is the chemical element with atomic number 41 and symbol Nb. It is a transition metal in period 5, group 5, with a standard atomic weight of 92.906 u.
Key facts
- Z
- 41
- Atomic weight
- 92.906 u
- Category
- transition metal
- State at 298 K
- Solid
- Occurrence
- primordial
- Discovered
- 1801
- CAS
- 7440-03-1
Measured properties
| Property | Value | Source |
|---|---|---|
| Electronegativity | 1.6 | National Center for Biotechnology Information (NIH) |
| Melting point | 2,750 K | National Center for Biotechnology Information (NIH) |
| Boiling point | 5,017 K | National Center for Biotechnology Information (NIH) |
| Density stp | 8.57 g/cm³ | National Center for Biotechnology Information (NIH) |
| Atomic radius empirical | 207 pm | National Center for Biotechnology Information (NIH) |
| Ionization energy 1st | 652.1 kJ/mol | National Center for Biotechnology Information (NIH) |
| Electron affinity | 86.2 kJ/mol | National Center for Biotechnology Information (NIH) |
Electron configuration
- Noble gas notation
- [Kr] 4d⁴ 5s¹
- Full notation
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁴ 5s¹
- Electrons per shell
- 2, 8, 18, 12, 1