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[ahyn-stahy-nee-uh m] /aɪnˈstaɪ ni əm/
noun, Chemistry, Physics.
a transuranic element. Symbol: Es; atomic number: 99.
Origin of einsteinium
1950-55; named after Albert Einstein; see -ium Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2016.
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British Dictionary definitions for einsteinium


a metallic transuranic element artificially produced from plutonium. Symbol: Es; atomic no: 99; half-life of most stable isotope, 252Es: 276 days
Word Origin
C20: New Latin, named after Albert Einstein
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for einsteinium



discovered in the debris of a 1952 U.S. nuclear test in the Pacific, named 1955 for physicist Albert Einstein (1879-1955).

Online Etymology Dictionary, © 2010 Douglas Harper
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einsteinium in Medicine

einsteinium ein·stein·i·um (īn-stī'nē-əm)
Symbol Es
A radioactive transuranic element synthesized by neutron irradiation of plutonium or other elements. Its longest-lived isotope is Es 254 with a half-life of 275 days. Atomic number 99; melting point 860°C.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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einsteinium in Science
Symbol Es
A synthetic, radioactive metallic element of the actinide series that is usually produced by bombarding plutonium or another element with neutrons. It was first isolated in a region near the explosion site of a hydrogen bomb. Its longest-lived isotope is Es 254 with a half-life of 276 days. Atomic number 99; melting point 860°C. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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