Tantalum (Ta)
Tantalum is the chemical element with atomic number 73 and symbol Ta. It is a transition metal in period 6, group 5, with a standard atomic weight of 180.95 u.
Key facts
- Z
- 73
- Atomic weight
- 180.95 u
- Category
- transition metal
- State at 298 K
- Solid
- Occurrence
- primordial
- Discovered
- 1802
- CAS
- 7440-25-7
Measured properties
| Property | Value | Source |
|---|---|---|
| Electronegativity | 1.5 | National Center for Biotechnology Information (NIH) |
| Melting point | 3,290 K | National Center for Biotechnology Information (NIH) |
| Boiling point | 5,731 K | National Center for Biotechnology Information (NIH) |
| Density stp | 16.4 g/cm³ | National Center for Biotechnology Information (NIH) |
| Atomic radius empirical | 217 pm | National Center for Biotechnology Information (NIH) |
| Ionization energy 1st | 761.3 kJ/mol | National Center for Biotechnology Information (NIH) |
| Electron affinity | 31.1 kJ/mol | National Center for Biotechnology Information (NIH) |
Electron configuration
- Noble gas notation
- [Xe] 4f¹⁴ 5d³ 6s²
- Full notation
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d³ 6s²
- Electrons per shell
- 2, 8, 18, 32, 11, 2