promethium

noun

pro·​me·​thi·​um prə-ˈmē-thē-əm How to pronounce promethium (audio)
: 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

Example Sentences

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

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'promethium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

Etymology

New Latin, from Latin Prometheus

First Known Use

1948, in the meaning defined above

Time Traveler
The first known use of promethium was in 1948

Dictionary Entries Near promethium

Cite this Entry

“Promethium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/promethium. Accessed 1 Feb. 2023.

Kids Definition

promethium

noun
pro·​me·​thi·​um prə-ˈmē-thē-əm How to pronounce promethium (audio)
: 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 How to pronounce promethium (audio)
: 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

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