Berkelium facts for kids

Berkelium (IPA:) is a chemical element in the periodic table. Berkelium has the symbol Bk and atomic number 97. It is a radioactive metallic element and an actinide. Berkelium was invented by scientists and does not exist in nature. Berkelium was first made by hitting americium with alpha particles or helium ions. It is named after Berkeley, California and the University of California, Berkeley.

, Albert Ghiorso, Stanley G. Thompson, and Kenneth Street, Jr at the University of California, Berkeley in December 1949. The team used a cyclotron to bombard a milligram-sized target of ²⁴¹Am with alpha particles to produce ²⁴³Bk (half-life 4.5 hours) and two free neutrons. One of the longest lived isotopes of the element, ²⁴⁹Bk (half-life 330 days), was later synthesized by subjecting a ²⁴⁴Cm target with an intense beam of neutrons.--> isotopes have half-lives that are less than 5 days, and the majority of these have half-lives that are less than 5 hours. This element also has 2 meta states, with the most stable being ^248mBk (t_½ 23.7 hours). The isotopes of berkelium range in atomic weight from 235.057 u (²³⁵Bk) to 254.091 u (²⁵⁴Bk).-->

Images for kids

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  Double-hexagonal close packing with the layer sequence ABAC in the crystal structure of α-berkelium (A: green, B: blue, C: red)

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  Glenn T. Seaborg

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  The 60-inch cyclotron at the Lawrence Radiation Laboratory, University of California, Berkeley, in August 1939

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  Chromatographic elution curves revealing the similarity between the lanthanides terbium (Tb), gadolinium (Gd), and europium (Eu) (top graph) and their corresponding actinides berkelium (Bk), curium (Cm), and americium (Am) (bottom graph)

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  22 milligrams of berkelium (as nitrate) prepared at HFIR in 2009 at a cost of approximately one million dollars, used for the synthesis of tennessine in JINR

See also

In Spanish: Berkelio para niños