Ununseptium

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Ununseptium is a chemical element, which was first produced artificially in nuclear research center in Dubna, near Moscow, 2010. The name corresponds to (Latin unus "one" (2 × ) and the Latin septem "seven" of ) 117 according to IUPAC rules for a systematic element name and the order number is up to the name by the first explorers provisional. It is also called Eka - astatine ("one under astatine ").

History

A 22 -milligram sample of berkelium ( 249Bk ) was created in 2009 in a 250 -day irradiation and then cleaned for 90 days at Oak Ridge National Laboratory. This sample resulted in the first six atoms of the element Ununseptium at the Joint Institute for Nuclear Research ( JINR ), Dubna, Russia, after a bombardment with calcium atoms in the U400 cyclotron for 150 days. Five atoms correspond to the isotope 293Uus, an atom of the isotope 294Uus. The decay times are 14 ms for the lighter isotope and 78 ms for the heavier isotope. This synthesis was a highlight of Russian-American cooperation between JINR and Lawrence Livermore National Laboratory in the synthesis of the elements 113-118, which was launched in 1989.