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einsteinium Syllabification: ein·stein·i·um
Pronunciation: /īnˈstīnēəm/

Definition of einsteinium in English:


The chemical element of atomic number 99, a radioactive metal of the actinide series. Einsteinium does not occur naturally and was discovered in 1953 in debris from the first hydrogen bomb explosion. (Symbol: Es)
Example sentences
  • They were named after two of the century's most creative physicists: einsteinium and fermium.
  • All isotopes of einsteinium are radioactive, the most stable being einsteinium - 252 with a half life of 20.47 days.
  • Atomic number 101 is a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles.


1950s: from the name of Albert Einstein, Albert + -ium.

Definition of einsteinium in:
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