Tantalum (Ta)

Atomic Model Details

Tantalum (Ta) is a transition metal with atomic number 73.

Atomic Number (Z): 73
- Number of Protons: 73
- Number of Electrons: 73 (in a neutral atom)
Atomic Mass (A): Approximately 180.948 u (for the most abundant isotope, Tantalum-181).
- Number of Neutrons: Varies by isotope. For Tantalum-181, it is 181 - 73 = 108 neutrons.
Atomic Radius (Metallic): Approximately 146 pm.

Electronic Configuration: [Xe] 4f¹⁴ 5d³ 6s²
- This configuration indicates that Tantalum has the electron configuration of Xenon ([Xe]) plus 14 electrons in the 4f subshell, 3 electrons in the 5d subshell, and 2 electrons in the 6s subshell.
Shell-wise Electron Distribution (Shell Diagram):
- K-shell (n=1): 2 electrons (1s²)
- L-shell (n=2): 8 electrons (2s² 2p⁶)
- M-shell (n=3): 18 electrons (3s² 3p⁶ 3d¹⁰)
- N-shell (n=4): 32 electrons (4s² 4p⁶ 4d¹⁰ 4f¹⁴)
- O-shell (n=5): 11 electrons (5s² 5p⁶ 5d³)
- P-shell (n=6): 2 electrons (6s²)
- The outermost shell (valence shell, P-shell) contains 2 electrons in the 6s subshell, and the penultimate shell (O-shell) contains 3 electrons in the 5d subshell, which are involved in its chemical bonding.

Ionization Enthalpy (First): Approximately 761 kJ/mol
- Tantalum has a relatively high first ionization enthalpy due to the strong attraction between the nucleus and the valence electrons.
Electronegativity (Pauling Scale): Approximately 1.5
- Tantalum exhibits moderate electronegativity, characteristic of a metallic element. It tends to lose electrons rather than gain them in chemical reactions.
Electron Gain Enthalpy: Typically positive or very low negative in magnitude.
- Metals generally have a very low tendency to accept additional electrons, thus their electron gain enthalpy is often positive, indicating energy input is required to add an electron, or slightly negative if an extremely stable configuration can be achieved. For Tantalum, it is not a significant property to consider for electron affinity.
Atomic Radius (Metallic): Approximately 146 pm
- Due to the lanthanoid contraction (poor shielding by 4f electrons), Tantalum’s atomic radius is unexpectedly similar to that of Niobium (Nb) in the preceding period, despite being heavier.

Density: 16.69 g/cm³ (at 20 °C)
- Tantalum is a very dense metal.
State at STP: Solid
Color: Silvery-blue-gray, lustrous metal
Melting Point: 3017 °C (3290 K)
- Tantalum has an exceptionally high melting point, one of the highest among all elements.
Boiling Point: 5458 °C (5731 K)
- Tantalum also possesses a very high boiling point.