Co
Cobalt · element 27
Transition Metal · Solid at room temperature
Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Key facts
Atomic mass
58.9331944 u
how heavy one atom is
Phase (room temp.)
Solid
Density
8.9 g/cm³
how tightly packed it is
Melting point
1768 K (1495 °C)
when solid turns to liquid
Boiling point
3200 K (2927 °C)
when liquid turns to gas
Period
4
its row in the periodic table
Group
9
its column in the periodic table
Block
D-block
the neighbourhood it lives in
Electronegativity
1.88
how strongly it pulls electrons
Electron configuration
[Ar] 3d7 4s2
where its electrons live
Shells
2 · 8 · 15 · 2
electrons in each layer, inside to out
Discovered by
Georg Brandt
who found it
Appearance
hard lustrous gray metal
what it looks like
Source: Wikipedia