Atomic symbol - Er
Atomic weight - 167.26
Atomic number - 68
Electron configuration - 2-8-18-30-8-2
Oxidation states - +3
State of matter - solid
Heavy metal-brittle
Discovered in 1843 by C.G. Mosander
Boils at 2510 .C, melts at 1522 .C

Notes:
Erbium is a metal with few uses. It is a grayish-silver color. It can be used
as an infra-red obsorbing glass and as an activator in some phosphoescent
materials.