Tantalum (Ta)
“Named after a mythical king who could never drink, this acid-proof metal hides by the dozen in your smartphone — and repairs human skulls.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
The notes
Characteristics
- Electron configuration [Xe] 4f¹⁴ 5d³ 6s² — period 6, group 5, d-block, five valence electrons; its signature oxidation state is +5, as in Ta₂O₅ and the tantalates.
- Chemically almost inert: below about 150 °C it shrugs off even aqua regia like glass, all thanks to a self-healing Ta₂O₅ passive film just nanometres thick.
- Very hard — among the hardest workable pure metals — and properly refractory too: melting point 3017 °C, density 16.69 g/cm³.
- The body accepts it without complaint: tantalum is so bio-inert that bone cells actually creep into its porous sponge and lock the implant in place.
A blue-grey, hard, heavy metal (density 16.69 g/cm³) with a steel-like lustre. Its surface grows an invisible film of Ta₂O₅ so tough that even boiling aqua regia leaves it unmoved — the metal behaves like a noble one despite being quite reactive underneath.
Where you meet it
✦ Uses
- Tantalum electrolytic capacitors — the tiniest farads in electronics, dozens of which pack every smartphone, laptop and car circuit board.
- Surgical implants: skull plates, bone-repair mesh, suture wire and porous “trabecular” hip and knee pieces that living bone grows into.
- Corrosion-proof chemical plant kit — heating coils and vessel linings that concentrate hydrochloric acid for years without pitting.
- Tantalum carbide hardens the edges of cutting tools, while ultrathin Ta₂O₅ coatings give camera lenses their glare-cutting, scratch-proof polish.
◍ Everyday examples
- Crack open a dead smartphone for recycling and the little beige “popcorn” beads on its circuit board are tantalum capacitors waiting to be reclaimed.
- A patient can spend the rest of life with a tantalum skull plate or hip implant — MRI scanners leave it completely unmoved.
- Much of the world’s coltan (columbite-tantalite ore) is dug in the DR Congo, which is why ethical-phone campaigns push so hard for tantalum recycling.
History & name
In 1802 the Swedish chemist Anders Gustaf Ekeberg extracted a stubborn new earth from minerals of Ytterby and Kimito that no acid would dissolve, and he reached for Greek myth: Tantalus, the king punished in Hades — thirsty with water up to his chin that always receded when he stooped to drink. The metal, like the king, would not “drink”. William Wollaston promptly insisted tantalum was nothing new, merely columbium again, and the muddle lasted forty years until Heinrich Rose proved in 1844 that two distinct elements hid in the old samples — naming the second niobium, after Niobe, Tantalus’s daughter, so father and daughter now sit side by side in group 5. Werner von Bolton first made pure ductile tantalum at Siemens in 1903, and it glowed as light-bulb filaments until tungsten took over.