Tantalum
TRANSITION METAL · GROUP 5 · PERIOD 6
73
Ta
Tantalum
180.95
Atomic Data
| Atomic Number | 73 |
| Symbol | Ta |
| Atomic Weight | 180.95 u |
| Density (STP) | 16.69 g/cm³ |
| Melting Point | 3016.85 °C (3290 K) |
| Boiling Point | 5457.85 °C (5731 K) |
| Electronegativity | 1.5 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2 |
| Oxidation States | +5 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 6 / 5 |
| CAS Number | 7440-25-7 |
Electron Configuration
{{BOHR_SVG}}
[Xe] 4f14 5d3 6s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| N | 4 | 4p | 6 | 36 |
| N | 4 | 4d | 10 | 46 |
| N | 4 | 4f | 14 | 60 |
| O | 5 | 5s | 2 | 62 |
| O | 5 | 5p | 6 | 68 |
| O | 5 | 5d | 3 | 71 |
| P | 6 | 6s | 2 | 73 |
| Total | 73 | 73 | ||
Isotopes of Tantalum
Tantalum has two naturally occurring stable isotopes. The most abundant is ¹⁸¹Ta, comprising 99.98799% of all naturally occurring Tantalum.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Tantalum-180 | ¹⁸⁰Ta | 73 | 107 | 0.01201 | Stable |
| Tantalum-181 | ¹⁸¹Ta | 73 | 108 | 99.98799 | Stable |
Abundance & Occurrence
Tantalum is present in Earth's crust at approximately 2 ppm by mass and at approximately 0.002 ppm by mass throughout the universe.
Earth's Crust (ppm by mass)
Tantalum
2 ppm
Silicon (ref.)
277,000 ppm
Oxygen (ref.)
461,000 ppm
Universe (ppm by mass)
Tantalum
0.002 ppm
Helium (ref.)
230,000 ppm
Hydrogen (ref.)
739,000 ppm
Discovery & History
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Safety & Handling
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Tantalum in the Real World
Real-World Uses
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Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.