The element samarium is named after the mineral samarskite from which it was first purified. However, another lanthanide-rich mineral called monazite is the main source of this element today. It is found as samarium phosphate, SmPO4. Samarium is mixed with cobalt to make permanent magnets often used in electric guitars.

Summary of properties (Sm)

Atomic weight150.36(2)
Discoverer (year)Lecoq de Boisbaudran, Paul-Émile (1879)
Natural formmetallic solid (rhombohedral)
Electron configuration[Xe] 46 6s2
Melting point (ºC)1072
Boiling point (ºC)1900
Abundance in earth's crust (ppm)7.05
Isotope (abundance)144Sm (3.07), 147Sm (14.99), 148Sm (11.24), 149Sm (13.82), 150Sm (7.38), 152Sm (26.75), 154Sm (22.75)
Density g/cm37.52
Van der Waals radius (pm)236
Covalent radius (pm)185
Electronegativity (Pauling)1.17
Vaporization enthalpy (kJ/mol)192.00
Enthalpy of fusion (kJ/mol)8.62
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.20
Thermal conductivity (W/cm·K) at 25ºC and 1 atm0.130
Oxidation state+3, +2
Electron affinity (eV)
1st Ionization potential (eV)5.6437

Back to the Periodic Table of the Elements.