Atomica
27Co58.933

Cobalt

Transition metals

Hard, shiny metals that conduct heat and electricity well and often form coloured compounds.

[Ar] 3d⁷ 4s²

Atomic number
27
Atomic mass
58.933
Protons
27
Neutrons
32 (most common)
Electrons
27
Shells
2, 8, 15, 2
State at 25 °C
Solid
Position
Group 9, period 4
Proton (+)Neutron (0)Electron (−)
Discovered byGeorg Brandt, about 1735Georg Brandt: 1 element

Miners blamed troublesome ores on the kobold, a goblin of German folklore. Brandt showed the problem was a new metal, and the name stuck.

Did you know?

  • Vitamin B12 has a cobalt atom at its centre.
  • Cobalt blue has coloured pottery for centuries.

Where it's found

  • Cobalt ores, often with copper and nickel

What it's used for

  • Lithium-ion battery cathodes
  • Deep blue glass and pottery
  • Jet engine alloys

Try it

There's no safe home experiment for Cobalt. Explore it with the animated atom above instead.