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SUPERHEAVY ELEMENTS Nielsbohrium, and

An international commission set up Following a proposal from the proposed) was found by and by IUPAP and IUPAC (International Russian Dubna Laboratory, element by Berkeley/Livermore teams, with Union of Pure and Applied Physics/ 107 was named nielsbohrium, 108 the Russian Laboratory given special ) in 1987 and chaired by hassium (after the Latin name credit. Sir Denys Wilkinson has published its 'Hassia', for GSI's home state of findings on the status of the ) and 109 meitnerium in transfermium elements (beyond honour of pioneer Lise 100) and the credit Meitner (1878-1968). for the various discoveries. In the commission's findings, The discovery of the three heaviest discovery of the element 101 elements, 107, 108 and 109, is () is attributed to attributed to 's GSI heavy Berkeley, 102 () to Dubna, Laboratory, in work carried out and 103 () to a decade of between 1981 and 1984 by a work at Berkeley and Dubna. The led by and Gottfried credit for element 104 (kurchatovium Munzenberg. After a proposal was or ) and 105 (provision­ submitted to IUPAC, the elements ally called hahnium) is shared be­ were formally named at a GSI tween Berkeley and Dubna. Element ceremony on 7 September. 106 (for which no name has yet been

Peter Armbruster (right) and Gottfried Munzenberg, leaders of the group which discovered elements 107, 108 and 109 at Darmstadt's GSI heavy ion Laboratory from 1981-4. At a GSI ceremony on 7 September, these respective names for these elements were formally adopted as nielsbohrium, hassium (after the Latin name 'Hassia', for GSI's home German state of Hesse) and meitnerium in honour of nuclear fission pioneer . (Photo Achim Zschau, GSI)

CERN Courier, November 1992 27