dubnium / hahnium

Element 105, is yet another (see rutherfordium) element swathed in Cold War competition and rivalry.

A team at the Soviet Joint Institute of Nuclear Research at Dubna in Russia was the first to synthesize element 105 in 1968. The team did not initially propose a name for the element, but eventually suggested nielsbohrium, with the chemical symbol Ns, after Danish physicist Niels Bohr (1885–1962).1

In 1970, a team at the University of California, Berkeley produced element 105 by a different method. The American team suggested the name hahnium, with the symbol Ha, after German chemist Otto Hahn (1879–1968). From a letter by Albert Ghiorso of Berkeley to Physical Review in 1970:

In honor of the late Otto Hahn we respectfully suggest that this new element be given the name hahnium.2

The findings of both groups were independently confirmed and credit for discovery was officially shared. But in 1997, the International Union of Pure and Applied Chemistry (IUPAC), which officially names the elements, rejected both suggested names (although element 107 was named bohrium), and decided on the name dubnium:

The discoveries of elements 104 and 105 are contested by Dubna and Berkeley. Both laboratories appear to have made significant contributions, but what has clearly emerged from the submissions, including those from Berkeley and from Darmstadt, is that the Dubna laboratory has played a key role in developing the experimental strategies used in synthesizing several transfermium elements. The Commission recommended that element 105 should be named dubnium in its honour. The Berkeley laboratory has already been similarly recognized on more than one occasion.3


1Encyclopedia Britannica, nielsbohrium, accessed 30 November 2009, http://dictionary.reference.com/browse/nielsbohrium

2Oxford English Dictionary, hahnium, 2nd Edition, 1989, Oxford University Press, accessed 30 November 2009, http://dictionary.oed.com/cgi/entry/50101424

3”Names and Symbols of Transfermium Elements (IUPAC Recommendations 1997),” Chemistry International, 1998, Vol. 20, No. 2, p. 38, http://www.iupac.org/publications/ci/1998/march/recent.pdf.

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