![Samarium element card: symbol Sm, atomic number 62, atomic mass 150.36, electron configuration [Xe] 4f⁶ 6s², oxidation states +3, Lanthanide, f-block, period 6, solid at room temperature.](https://stage.chemistry-dictionary.com/wp-content/uploads/2026/09/samarium-chemical-element.webp)
Samarium sits in the f-block of the periodic table, where atoms fill their inner f-orbitals with electrons. In most chemical compounds, samarium atoms lose three electrons to form ions with a +3 charge. These compounds usually look pale yellow when dissolved in water or sitting on a lab shelf.
However, samarium can also form stable compounds with a +2 charge. This low charge is very unusual for lanthanide elements, which typically prefer the +3 state. A great example of this is samarium(II) iodide, a useful compound that chemists call Kagan’s reagent.
This compound acts as a powerful reducing agent by giving away single electrons to other molecules. Chemists use it in organic synthesis to build complex structures by linking carbon atoms. In nature, samarium never exists as a pure metal because it is too reactive.
Instead, it hides inside complex minerals such as monazite and bastnasite. Mining companies use acid treatments and solvent extraction to separate samarium from other rare metals. A common student misconception is that rare-earth elements are extremely scarce in the earth.
Actually, samarium is more common than metals like tin or cobalt. Pure samarium is also highly effective at absorbing neutrons, which are neutral particles inside atom nuclei. This property makes it perfect for control rods that regulate nuclear reactions inside power plants. The metal is also naturally magnetic, although its magnetic pull is weaker than other rare-earth metals.