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73Ta180.9479
Transition metal

Tantalum

Tantalum is a hard, dense, blue-gray transition metal discovered in 1802 and named after Tantalus from Greek mythology, thanks to how stubbornly its oxide resisted dissolving in acid. It's prized for extreme corrosion resistance and shows up in nearly every modern smartphone.

Group · Period
5 · 6
At room temp
solid
Melts at
3290 K
Density
16.4 g/cm³
Discovered
1802

Uses

Tantalum’s defining industrial use is in capacitors — tiny components that store electrical charge — because tantalum forms an extremely stable, thin oxide layer that makes for small, reliable, high-performance capacitors. That’s why tantalum capacitors are found inside most smartphones, laptops, and other compact electronics, where space is tight and reliability matters. Tantalum is also remarkably resistant to corrosion from acids and other aggressive chemicals, which makes it useful for linings and components in chemical processing equipment, and that same inertness makes it biocompatible enough for surgical implants, including plates used in skull repair and modern porous implants used in orthopedic surgery.

History

Tantalum was discovered in 1802 by Swedish chemist Anders Gustaf Ekeberg, who identified it in mineral samples from Scandinavia and Finland. Ekeberg noted that the new element’s oxide was extraordinarily resistant to dissolving in acid, refusing to react no matter what he tried, and he named it after Tantalus, the figure from Greek mythology who was eternally denied the food and water in front of him. For decades afterward, tantalum was easily confused with the chemically similar element niobium, discovered around the same time, and it took further research to clearly establish them as two distinct elements.

Fun facts

  • Tantalum was named after Tantalus, a figure from Greek mythology, because its oxide 'tantalizingly' refused to dissolve in the acids early chemists tried.
  • Tiny tantalum capacitors are used in most smartphones and laptops because they pack a lot of capacitance into a very small space.
  • Tantalum is so resistant to corrosion that surgeons use it to make implants the body tolerates extremely well.

Frequently asked questions

Why is tantalum used in electronics?

Tantalum forms a very stable, thin oxide layer on its surface, which makes excellent capacitors — components that store and release small amounts of electrical charge. Tantalum capacitors are reliable and can be made very small while still holding a useful amount of charge, which is exactly what's needed inside compact devices like smartphones, laptops, and cameras.

What does tantalum have to do with the human body?

Because tantalum barely reacts with anything, including body fluids, it's considered highly biocompatible. It's been used for decades in surgical applications, including plates for skull repair and modern porous tantalum implants used in orthopedic surgery, since the body tends to tolerate it extremely well without irritation or rejection.

How did tantalum get its unusual name?

When Swedish chemist Anders Gustaf Ekeberg identified tantalum in 1802, its oxide proved remarkably resistant to dissolving in acid, no matter how it was treated. That stubbornness reminded him of Tantalus, the figure from Greek mythology condemned to reach for food and water that always stayed just out of reach — a fitting name for an element that resisted every attempt to make it react.

Compounds

3 notable compounds containing Ta

  • TaCindustrial

    Tantalum carbide

    An extremely hard, brownish-grey ceramic with one of the highest melting points of any known material, making it valuable wherever extreme heat and wear resistance are required.

    Used for: Wear-resistant coatings on cutting tools and ultra-high-temperature components

  • TaCl5halide

    Tantalum pentachloride

    A pale yellow, moisture-sensitive solid that fumes in humid air, used as the principal starting material for making other tantalum compounds.

    Used for: Precursor for high-purity tantalum metal and tantalum oxide films

  • Ta2O5oxide

    Tantalum pentoxide

    A chemically stable white oxide with a high dielectric constant, formed as a thin insulating layer on tantalum metal that gives tantalum capacitors their reliability.

    Used for: Dielectric layer in tantalum electrolytic capacitors for electronics

Isotopes

40 known isotopes

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IsotopeNatural abundanceHalf-lifeDecay modeMass excessBinding energy / nucleonDecay width
Ta-181 stable 99.98799% Stable — -48,439.06 keV 8,023.41 keV —
Show all 40 isotopes
Ta-155 — 2.9 ms Proton emission (100%) -23,988 keV 7,858 keV 1.57 × 10-13 eV
Ta-156 — 106 ms Proton emission (71%), Electron capture / beta-plus decay (29%) -26,001 keV 7,872 keV 4.30 × 10-15 eV
Ta-157 — 10.1 ms Alpha decay (96.6%), Proton emission (3.4%) -29,595.95 keV 7,896.06 keV 4.52 × 10-14 eV
Ta-158 — 55 ms Alpha decay (91%), Electron capture / beta-plus decay (9%) -31,118 keV 7,907 keV 8.30 × 10-15 eV
Ta-159 — 0.83 s Electron capture / beta-plus decay (66%), Alpha decay (34%) -34,439.16 keV 7,928.73 keV 5.50 × 10-16 eV
Ta-160 — 1.55 s Alpha decay (34%) -35,823.7 keV 7,938.27 keV 2.94 × 10-16 eV
Ta-161 — — Alpha decay, Electron capture / beta-plus decay -38,778.58 keV 7,957.45 keV —
Ta-162 — 3.57 s Electron capture / beta-plus decay (99.926%), Alpha decay (0.074%), ECP -39,781.41 keV 7,964.34 keV 1.28 × 10-16 eV
Ta-163 — 10.6 s Electron capture / beta-plus decay (99.8%), Alpha decay (0.2%) -42,534.63 keV 7,981.89 keV 4.30 × 10-17 eV
Ta-164 — 14.2 s Electron capture / beta-plus decay (100%), Alpha decay -43,282.81 keV 7,987 keV 3.21 × 10-17 eV
Ta-165 — 31.0 s Electron capture / beta-plus decay (100%) -45,847.87 keV 8,003.05 keV 1.47 × 10-17 eV
Ta-166 — 34.4 s Electron capture / beta-plus decay (100%) -46,097.78 keV 8,004.97 keV 1.33 × 10-17 eV
Ta-167 — 80 s Electron capture / beta-plus decay (100%) -48,351.06 keV 8,018.86 keV 5.70 × 10-18 eV
Ta-168 — 2.0 m Electron capture / beta-plus decay (100%) -48,393.91 keV 8,019.43 keV 3.80 × 10-18 eV
Ta-169 — 4.9 m Electron capture / beta-plus decay (100%) -50,290.44 keV 8,030.96 keV 1.55 × 10-18 eV
Ta-170 — 6.76 m Electron capture / beta-plus decay (100%) -50,137.67 keV 8,030.3 keV 1.12 × 10-18 eV
Ta-171 — 23.3 m Electron capture / beta-plus decay (100%) -51,720.28 keV 8,039.79 keV 3.26 × 10-19 eV
Ta-172 — 36.8 m Electron capture / beta-plus decay (100%) -51,329.98 keV 8,037.71 keV 2.07 × 10-19 eV
Ta-173 — 3.14 h Electron capture / beta-plus decay (100%) -52,396.54 keV 8,044.07 keV 4.04 × 10-20 eV
Ta-174 — 1.14 h Electron capture / beta-plus decay (100%) -51,740.77 keV 8,040.45 keV 1.11 × 10-19 eV
Ta-175 — 10.5 h Electron capture / beta-plus decay (100%) -52,408.65 keV 8,044.45 keV 1.21 × 10-20 eV
Ta-176 — 8.09 h Electron capture / beta-plus decay (100%) -51,365.38 keV 8,038.67 keV 1.57 × 10-20 eV
Ta-177 — 56.36 h Electron capture / beta-plus decay (100%) -51,714.75 keV 8,040.83 keV 2.25 × 10-21 eV
Ta-178 — 2.36 h Electron capture / beta-plus decay (100%) -50,598 keV 8,035 keV 5.37 × 10-20 eV
Ta-179 — 1.82 Y Electron capture (100%) -50,357.46 keV 8,033.59 keV 7.94 × 10-24 eV
Ta-180 — 8.154 h Electron capture (85%), Beta-minus decay (15%) -48,933.63 keV 8,025.89 keV 1.55 × 10-20 eV
Ta-182 — 114.74 d Beta-minus decay (100%) -46,430.69 keV 8,012.63 keV 4.60 × 10-23 eV
Ta-183 — 5.1 d Beta-minus decay (100%) -45,293.55 keV 8,006.74 keV 1.04 × 10-21 eV
Ta-184 — 8.7 h Beta-minus decay (100%) -42,839.45 keV 7,993.75 keV 1.46 × 10-20 eV
Ta-185 — 49.4 m Beta-minus decay (100%) -41,394.37 keV 7,986.36 keV 1.54 × 10-19 eV
Ta-186 — 10.39 m Beta-minus decay (100%) -38,607.6 keV 7,971.84 keV 7.32 × 10-19 eV
Ta-187 — 283 s Beta-minus decay (100%) -36,895.55 keV 7,963.21 keV 1.61 × 10-18 eV
Ta-188 — 19.6 s Beta-minus decay (100%) -33,910 keV 7,948 keV 2.33 × 10-17 eV
Ta-189 — — Beta-minus decay (100%) -31,960 keV 7,938 keV —
Ta-190 — 5.3 s Beta-minus decay (100%) -28,720 keV 7,922 keV 8.61 × 10-17 eV
Ta-191 — 300 ns Beta-minus decay -26,520 keV 7,911 keV 1.52 × 10-9 eV
Ta-192 — 2.2 s Beta-minus decay (100%) -23,100 keV 7,894 keV 2.07 × 10-16 eV
Ta-193 — — Beta-minus decay (100%), Beta-minus, neutron emission -20,810 keV 7,883 keV —
Ta-194 — — Beta-minus decay (100%), Beta-minus, neutron emission -17,130 keV 7,865 keV —