Periodic Table of the elements main page

Periodic Table

science park

Table of Elements

Chemical information

Science dictionary

scientific data

Site map

Gifts and souvenirs

printable version

go to periodic table










Education Billboard - meet and serve your education needs

Element Fact
Selenium is an essential trace element in the diets that acts as antioxidants.

Erbium, Er

erbium sample

Atomic number: 68
Atomic mass: 167.259(3)
Natural abundance: 3.5 ppm
162Er (161.928775) - 0.14%
164Er (163.929197) - 1.61%
166Er (165.930290) - 33.6%
167Er (166.932045) - 22.95%
168Er (167.932368) - 26.8%
170Er (169.935460) - 14.9%

History and Production

The name was derived from a Swedish village Ytterby. Discovered in 1843 as an oxide from gadolinite by C.G. Mosander. Fairly pure oxide (Er2O3) was only isolated in 1905 by C. James and independently by G. Urbain. The metal salts can be extracted from minerals such as xenotime and euxenite by ion-exchange methods. The metal can be recovered by reduction of the fluoride with calcium metal. There are only few commercial uses for the metal so far. It is used as an additive to vanadium to lower hardness and improve workability. The oxide is used as a colorant (pink) in glasses and porcelain enamel glazes.

Physical Data

The metal is grayish silver in color. It is relatively stable in air compare with other lanthanides. At low temperatures the element is antiferromagnetic and becomes ferromagnetic and superconductive at very low temperatures. It consists of 3.5 ppm of the earth's crustal rocks, often associates with other rare earth minerals.

Interatomic distance: 346.8 pm
Melting point: 1529C
Boiling point: 2868C
Thermal conductivity/Wm-1K-1: 14.3 (27C)
Density/kgm-3: 9066 (25C)

Standard Thermodynamic Data (atomic gas)

Enthalpy of formation: 317.1 kJ/mol
Gibbs free energy of formation: 280.7 kJ/mol
Entropy: 195.6 J/mol K
Heat capacity: 20.8 J/mol K

Electronic data

Electronic configuration: [Xe] 4f12 6s2
Term symbol: 3H6
Electron affinity: -   Electronegativity (Pauline): 1.24
Ionization energy (first, second, third): 589.304, 1151.07, 2194.08 kJ/mol

Chemical properties

| Copyright | Privacy | Disclaimer | Contact |

2004-2010, all rights reserved.