Tantalum (Ta)

Tantalum capacitors pack more capacitance into less space than almost anything else and barely drift with age or temperature, which is why they are still specified for anything that has to keep working — implanted defibrillators, avionics, hearing aids. The metal is so unreactive that the body does not attack it, so tantalum plates have been used to repair skulls since the 1940s. Named after Tantalus, condemned to stand in water he could not drink: the oxide will not absorb acid no matter how long it stands in it.

Properties

Atomic number

73

Symbol

Ta

Standard atomic weight

180.95 u

Category

Transition metal

Group

5

Period

6

Block

d-block

Electron configuration

[Xe] 6s² 4f¹⁴ 5d³

Electrons per shell

2, 8, 18, 32, 11, 2

Melting point

3,290 K — 3016.8 °C — 5462.3 °F

Boiling point

5,731 K — 5457.9 °C — 9856.1 °F

Density

16.4 g/cm³

Electronegativity

1.5 (Pauling)

Oxidation states

+5

Discovered

1802 by Anders Gustaf Ekeberg

Electron configuration

Full

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d³

Noble gas shorthand

[Xe] 6s² 4f¹⁴ 5d³

Shells

K: 2 · L: 8 · M: 18 · N: 32 · O: 11 · P: 2

What it is used for

• Tantalum capacitors in phones, laptops and hearing aids
• Surgical implants, plates and sutures
• Chemical plant linings for hot concentrated acids
• Carbide cutting tool additives
• Vacuum furnace parts and rocket nozzles

Most tantalum comes from coltan ore, some of it mined in eastern Congo under conditions that made it one of the original "conflict minerals" named in US disclosure rules.

Neighbours in the table

Group 5

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Tantalum sits in group 5 with vanadium, niobium, dubnium.