Tantalum (Ta)
Tantalum is element 73, a transition metal in period 6, group 5 of the periodic table. At room temperature it is a solid.
Electron configuration [Xe] 4f14 5d3 6s2
Electrons per shell 2, 8, 18, 32, 11, 2
Tantalum data
| Atomic number | 73 |
|---|---|
| Symbol | Ta |
| Atomic mass | 180.948 u |
| Category | Transition metal |
| Group | 5 |
| Period | 6 |
| Block | d |
| State at 25 °C | solid |
| Melting point | 3290 K (3016.9 °C) |
| Boiling point | 5731 K (5457.9 °C) |
| Density | 16.65 g/cm³ |
| Electronegativity (Pauling) | 1.5 |
| Atomic radius | 138 pm |
| 1st ionization energy | 761 kJ/mol |
| Electron affinity | -31 kJ/mol |
| Oxidation states | -1, +2, +3, +4, +5 |
| Common ion charge | 5+ |
| Discovered | 1802 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through tantalum’s configuration and its ions →
Where tantalum sits
Tantalum belongs to the transition metals. Its Pauling electronegativity of 1.5 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Tantalum FAQ
What is the electron configuration of tantalum?
Tantalum (Z = 73) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d3 6s2. In noble-gas shorthand that is [Xe] 4f14 5d3 6s2.
How many valence electrons does tantalum have?
5 (2 outer s + 3 d electrons; 2 in the outermost shell).
What is the atomic mass of tantalum?
The standard atomic weight of tantalum is 180.948 u, so one mole weighs 180.948 g.
Is tantalum a metal?
Yes. Tantalum is a transition metal.
What is the charge of a tantalum ion?
Tantalum most commonly forms Ta5+.