Tantalum (Ta)
Element 73 · transition metal · group 5, period 6
Tantalum is element 73, a transition metal in group 5 and period 6. Its electron configuration is [Xe] 4f14 5d3 6s2. The shells fill 2, 8, 18, 32, 11, 2. Courses differ here. Counting only the outer s subshell gives 2; counting the inner d subshell with it gives 5, which is the group number. It commonly forms ions with a charge of +5.
- 73 protons
- 2/5 valence e−
- +5
- d-block
Properties
| Atomic number | 73 |
|---|---|
| Symbol | Ta |
| Standard atomic weight | 180.95 u |
| Group | 5 |
| Period | 6 |
| Block | d-block |
| Category | transition metal |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2 |
| Noble-gas notation | [Xe] 4f14 5d3 6s2 |
| Electrons per shell | 2, 8, 18, 32, 11, 2 |
| Valence electrons | 2 or 5 |
| Common ionic charge | +5 |
| Electronegativity (Pauling) | 1.5 |
| Protons / electrons | 73 / 73 |
Electron configuration of tantalum
Orbitals fill from the lowest energy upward. Writing that out for tantalum gives 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2, which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2 in plain text.
Everything up to Xe is the same as in that noble gas, so it is usually abbreviated to [Xe] 4f14 5d3 6s2. The part outside the bracket is what does the chemistry.
| Subshell | Electrons | Capacity |
|---|---|---|
| 1s | 2 | 2 |
| 2s | 2 | 2 |
| 2p | 6 | 6 |
| 3s | 2 | 2 |
| 3p | 6 | 6 |
| 3d | 10 | 10 |
| 4s | 2 | 2 |
| 4p | 6 | 6 |
| 4d | 10 | 10 |
| 4f | 14 | 14 |
| 5s | 2 | 2 |
| 5p | 6 | 6 |
| 5d | 3 | 10 |
| 6s | 2 | 2 |
Tantalum ion charge
Tantalum commonly forms ions with a charge of +5.
Common questions
How many valence electrons does tantalum have?
There is no single agreed answer for tantalum. Courses differ here. Counting only the outer s subshell gives 2; counting the inner d subshell with it gives 5, which is the group number. Check which convention your course uses before answering.
What is the electron configuration of tantalum?
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2, or [Xe] 4f14 5d3 6s2 written from the previous noble gas. Orbitals fill lowest energy first.
What is the charge of tantalum?
Tantalum commonly forms ions with a charge of +5. Transition metals have several accessible oxidation states, which is why more than one charge is listed.
How many protons, electrons and neutrons does tantalum have?
A neutral tantalum atom has 73 protons and 73 electrons. Its standard atomic weight is 180.95, so the most common isotope has about 108 neutrons.
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