27 Co 58.933

Cobalt

Transition Metal

Cobalt (Co) is a chemical element with atomic number 27, classified as a transition metal. At room temperature it is a solid. It was discovered in 1735 by Georg Brandt.

Properties

Atomic number
27
Atomic mass
58.933 u
Category
Transition Metal
Group
9
Period
4
Block
d-block
Electron configuration
[Ar] 3d⁷ 4s²
Phase at STP
Solid
Density
8.86 g/cm³
Melting point
1768 K (1494.8 °C)
Boiling point
3200 K (2926.8 °C)
Electronegativity
1.88
Atomic radius
152 pm
Ionization energy
7.881 eV
Discovery
1735 · Georg Brandt

Common uses

Batteries, magnets, blue pigments, medical implants

Did you know?

Critical for lithium-ion batteries and creates brilliant blue glass.