promethium

promethium definition - medical

pro·me·thi·um (prə-mēˈthē-əm)

noun Symbol Pm
A radioactive rare-earth element prepared by fission of uranium. Pm 145 is the longest-lived isotope with a half-life of 17.7 years. Atomic number 61.

The American Heritage® Medical Dictionary Copyright © 2009 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

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