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promethium
noun
pro·me·thi·um
prə-ˈmē-thē-əm
: a radioactive metallic element of the rare-earth group obtained as a fission product of uranium or from neutron-irradiated neodymium see Chemical Elements Table
Examples of promethium in a Sentence
Recent Examples on the Web
Yttrium is twice as abundant as lead; all of the rare-earth metals (with the exception of radioactive promethium) are more common than silver.
—Hugh Aldersey-Williams, Discover Magazine, 21 Sep. 2011
Carl Sagan and Iosef Shklovskii, along with Frank Drake, had raised the idea of looking for radioactive elements like promethium in stars as a possible alien signal.
—Corey S Powell, Discover Magazine, 1 July 2017
One promethium isotope, with eighty-eight neutrons, has a half-life of a few days; the other, with eighty-six neutrons, has a half-life of a few years.
—Neima Jahromi, The New Yorker, 27 Dec. 2019
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Word History
Etymology
New Latin, from Latin Prometheus
First Known Use
1948, in the meaning defined above
Dictionary Entries Near promethium
Cite this Entry
“Promethium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/promethium. Accessed 23 Dec. 2024.
Kids Definition
promethium
noun
pro·me·thi·um
prə-ˈmē-thē-əm
: a radioactive metallic element obtained from the splitting of uranium atoms see element
Medical Definition
promethium
noun
pro·me·thi·um
prə-ˈmē-thē-əm
: a radioactive metallic element of the rare-earth group obtained as a fission product of uranium or from neutron-irradiated neodymium
—symbol Pm
see Chemical Elements Table
More from Merriam-Webster on promethium
Britannica.com: Encyclopedia article about promethium
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