Chemical Element: einsteinium

(Modern Latin: chemical element; named for Albert Einstein; radioactive metal)

Chemical-Element Information

Symbol: Es
Atomic number: 99
Year discovered: 1952

Discovered by: Albert Ghiorso (born July 15, 1915) and co-workers; at Argonne, Los Alamos, New Mexico and the University of California at Berkeley.


  • Einsteinium was identified by Ghiorso and others at the University of California in Berkeley, California, in 1952.
  • It was found in radioactive debris from the first large thermonuclear bomb explosion, which took place in the Pacific on November, 1952.
  • In 1961, a sufficient amount of einsteinium was produced to permit separation of a macroscopic amount of isotope Es.

Name in other languages:

French: einsteinium

German: Einsteinium

Italian: einsteinio

Spanish: einsteinio


Information about other elements may be seen at this Chemical Elements List.

A special unit about words that include chemo-, chem- may be seen here.