The name of the element is 'Einsteinium', its symbol is Es and the atomic number is 99. Named in honour of Albert Einstein, it is the seventh transuranic element and does not occur naturally in any measurable quantities. Einsteinium was first identified in December 1952 by Albert Ghiorso, with co-workers at the University of California, Berkeley, when he was examining debris from the first hydrogen bomb test of November 1952.