The periodic table/Samarium

The element Samarium
Subject classification: this is a chemistry resource.
Educational level: this is a research resource.
Type classification: this is an article resource.
Completion status: this resource is considered to be complete.

Discovery Edit

  • Paul-Émile Lecoq de Boisbaudran isolated a samarium salt in 1879 in Paris, France.
  • First, Boisbaudran extracted ‘didymium’ from the mineral samarskite and made a solution of ‘didymium’ nitrate. He then added ammonium hydroxide and found two precipitates were formed; one containing ‘didymium’ and the other a new element – samarium.
  • The new element samarium was named after the mineral samarskite in which it had been found.

Quick Facts Edit

Name: Samarium

Symbol: Sm

Mass: 150.36

Classification: Lanthanides

Protons: 62

Electrons: 62

Neutrons: 88

Color: silvery-white

Discovered in: 1879

Electron Configuration: Xe 4f6 6s2

CAS Number: 7440-19-9

Appearance: silvery-white metal

Key Isotopes: 152Sm

Allotropes: α-samarium, β-samarium, γ-samarium

Density: 7.54 grams per cubic centimeter

Crystal Structure: ​rhombohedral

Melting Point: 1,074°C

Boiling Point: 1,794°C

Uses Edit

  • Samarium is used as a catalyst for the dehydration and dehydrogenation of ethanol, and is also used in infrared absorbing glass.
  • Radioactive 153Samarium is used in the treatment of cancer.
  • Samarium is used as an absorb-er in nuclear reactors.
  • Main use of Samarium is in samarium-cobalt alloy magnets. These magnets are resistant to demagnetization.

Atomic Data Edit

Atomic radius: 229 pm

Covalent radius: 198 pm

Electronegativity: 1.17

Electron affinity: 0.162 (theoretical)

Ionisation energies

First: 1st: 544.5 kJ/mol

Second: 2nd: 1070 kJ/mol

Third: 3rd: 2260 kJ/mol

Supply Risk Edit

Relative supply risk: 9.5

Crustal abundance: 0.3 ppm

Recycling rate: <10%

Substitutability: High

Production concentration: 97%

Reserve distribution: 50%

Oxidation States and Isotopes Edit

Common oxidation states: 3, 2


Isotope Atomic mass Abundance (%) Half life Mode of decay
144Sm 143.912 3.07
147Sm 146.915 14.99
148Sm 147.915 11.24
149Sm 148.917 13.82
150Sm 147.915 11.24
148Sm 147.915 11.24
148Sm 147.915 11.24

External Links Edit

  Search for Samarium on Wikipedia.