Sm
Samarium is used in powerful magnets and cancer treatment.
Physical Properties
| Atomic Mass | 150.36 u |
| Density | 7.52 g/cm³ |
| Melting Point | 1345.0 K |
| Boiling Point | 2067.0 K |
| Appearance | Silvery-white metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.17 (Pauling) |
| 1st Ionization Energy | 544.5 kJ/mol |
| Electron Affinity | 15.6 kJ/mol |
| Oxidation States | +2, +3 |
Atomic Properties
| Electron Configuration | [Xe] 4f6 6s2 |
| Atomic Radius | 180.0 pm |
| Covalent Radius | 198.0 pm |
| Van der Waals Radius | 229.0 pm |
Discovery
| Discovered By | Lecoq de Boisbaudran |
| Discovery Year | 1879 |
| Location | Paris, France |
| Named After | Named after the mineral samarskite, after Russian official Vasili Samarsky-Bykhovets |
About Samarium
Samarium is a moderately hard silvery metal that slowly oxidizes in air. Samarium-cobalt magnets were the first rare earth magnets and remain important for high-temperature applications.
Uses & Applications
Samarium-cobalt magnets, cancer treatment (samarium-153), nuclear reactor control rods, and catalysts.
Fun Fact
Samarium-cobalt magnets operate at up to 700 degrees C, far exceeding neodymium magnets, making them essential for jet engines.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 147 | 0.1499% | 1.06e11 years | No |
| 149 | 0.1382% | - | Yes |
| 150 | 0.0738% | - | Yes |
| 152 | 0.2675% | - | Yes |
Electron Configuration
[Xe] 4f6 6s2