samarium-149

chemical isotope

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Last updated

July 13, 2026

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Samarium-149 is a chemical isotope of samarium, a rare-earth metal found in the lanthanide series of the periodic table. Samarium is a silvery-white metal that is relatively stable in air.12

Samarium-149 is one of the seven naturally occurring isotopes of samarium. While samarium-144, samarium-150, samarium-152, and samarium-154 are stable, samarium-147, samarium-148, and samarium-149 are alpha emitters. Samarium-149 has a very long half-life, making it useful in nuclear reactors for control rods and neutron shielding due to its high absorption cross section for thermal neutrons.13

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samarium
2 percent), samarium-149 (13.8 percent), samarium-150 (7.4 percent), samarium-152 (26.8 percent), and samarium-154 (22.0 percent). Samarium-144, samarium-150, samarium-152, and samarium-154 are stable, but the other three naturally occurring isotopes are alpha emitters. A total of 34 (excluding nuclear isomers) radioactive isotopes of samarium have been characterized. Their…
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2 percent), samarium-149 (13.8 percent), samarium-150 (7.4 percent), samarium-152 (26.8 percent), and samarium-154 (22.0 percent). Samarium-144, samarium-150, samarium-152, and samarium-154 are stable, but the other three naturally occurring isotopes are alpha emitters. A total of 34 (excluding nuclear isomers) radioactive isotopes of samarium have been characterized. Their…
Read More