The periodic table/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
editName: 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
editAtomic 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
editRelative supply risk: 9.5 Crustal abundance: 0.3 ppm Recycling rate: <10%
|
Substitutability: High Production concentration: 97% Reserve distribution: 50% |
Oxidation States and Isotopes
editCommon oxidation states: 3, 2
Isotopes
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 |