Like terbium and ytterbium, erbium is also named after the Swedish town of Ytterby, near which it was discovered. This element does not occur in its pure form in nature, but can be obtained from the mineral monazite. Many erbium compounds are pink in color and are used to color ceramics and glass.

Summary of properties (Er)

Atomic weight167.259(3)
Discoverer (year)Mosander, Carl Gustav (1842)
Natural formmetallic solid (hexagonal)
Electron configuration[Xe] 412 6s2
Melting point (ºC)1522
Boiling point (ºC)2510
Abundance in earth's crust (ppm)3.5
Isotope (abundance)162Er (0.139), 164Er (1.601), 166Er (33.503), 167Er (22.869), 168Er (26.978), 170Er (14.910)
Density g/cm39.07
Van der Waals radius (pm)229
Covalent radius (pm)177
Electronegativity (Pauling)1.24
Vaporization enthalpy (kJ/mol)293.00
Enthalpy of fusion (kJ/mol)19.90
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.17
Thermal conductivity (W/cm·K) at 25ºC and 1 atm0.150
Oxidation state+3
Electron affinity (eV)
1st Ionization potential (eV)6.1077

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