Discovery of berkelium

Berkelium was synthesised in 1949 at the University of California, Berkeley, by Stanley Thompson, Albert Ghiorso and Glenn Seaborg, who bombarded americium-241 with alpha particles in the university's cyclotron. It had atomic number 97 and was the fifth transuranium element to be discovered, produced only a few weeks before californium. Its name honours the city of Berkeley, home of the laboratory, in the same way that terbium, its counterpart in the rare earth series, was named after Ytterby. Berkelium is a soft, silvery, radioactive metal that is made in small quantities in nuclear reactors. It has no commercial uses, but it was used in 2009 and 2010 as the target in the first experiments that created element 117, tennessine.

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