Cr
Chromium · element 24
Transition Metal · Solid at room temperature
Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point.
Key facts
Atomic mass
51.99616 u
how heavy one atom is
Phase (room temp.)
Solid
Density
7.19 g/cm³
how tightly packed it is
Melting point
2180 K (1907 °C)
when solid turns to liquid
Boiling point
2944 K (2671 °C)
when liquid turns to gas
Period
4
its row in the periodic table
Group
6
its column in the periodic table
Block
D-block
the neighbourhood it lives in
Electronegativity
1.66
how strongly it pulls electrons
Electron configuration
[Ar] 3d5 4s1
where its electrons live
Shells
2 · 8 · 13 · 1
electrons in each layer, inside to out
Discovered by
Louis Nicolas Vauquelin
who found it
Appearance
silvery metallic
what it looks like
Source: Wikipedia