62
150.36
Sm
Samarium
Identification
CAS Number: 7440-19-9
Discovery Year: 1879
Discoverer: Paul Émile Lecoq de Boisbaudran
Discovery Location: France
Properties
Atomic Dimensions
Atomic Radius: 185 pm →
Atomic Radius (Rahm): 280 pm
Covalent Radius: 198 pm →Van der Waals Radius: 236 pm
Atomic Volume: 19.9 cm³/mol
Lattice Constant: 9 Å
Thermodynamics
Electronic Structure
Abundance & Geochemistry
Crust Abundance: 7.05 mg/kg
Sea Abundance: 4.5e-7 mg/L
Geochemical Class: rare earth & related
Goldschmidt Class: litophile
About
Soft silvery metallic element, belongs to the lanthanoids. Seven natural isotopes, Sm-147 is the only radioisotope, and has a half-life of 2.5*10^11 years. Used for making special alloys needed in the production of nuclear reactors. Also used as a neutron absorber. Small quantities of samarium oxide is used in special optical glasses. The largest use of the element is its ferromagnetic alloy which produces permanent magnets that are five times stronger than magnets produced by any other material. Discovered by Francois Lecoq de Boisbaudran in 1879.
Isotopes
Sm-152 152 26.74%
Sm-154 154 22.74%
Sm-147 147 15.00%
Sm-149 149 13.82%
Sm-148 148 11.25%
Sm-150 150 7.37%
Sm-144 144 3.08%
