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n. Symbol Mc
An artificially produced radioactive element with atomic number 115 whose most stable isotope has a mass number of 289 and a half-life of 220 milliseconds.
[New Latin Moscovia, Moscow, Muscovy (probably from Old Russian Moskovĭ, accusative of *Mosky, Moscow, source of Modern Russian Moskva, Moscow) + -ium (so called because it was first synthesized at the Joint Institute for Nuclear Research in Dubna, in the Moscow region).]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.