14 July 2023
Of all the chemical elements, the histories of the names of elements 104 and 105 are perhaps the most complex. The naming of these elements was mired in Cold War competition between the Soviet Union and the United States. Both elements are synthetic, not found in nature, and with short half-lives which makes them unsuitable for purposes other than pure research.
Element 104 was first created in 1964 by scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and they proposed the name kurchatovium for it, after nuclear physicist Igor Kurchatov. But the Soviet claim was not widely accepted in the West.
Six years later, an American team at the Lawrence Radiation Laboratory in Berkeley California synthesized element 104 and proposed the name rutherfordium and the symbol Rf, after the chemist Ernest Rutherford. But because of the competing Soviet claim of discovery, the International Union of Pure and Applied Chemistry (IUPAC) did not give the element an official name for several decades.
In 1968 scientists at the JINR synthesized element 105. They published the finding in 1971 but did not propose a name for the element at that time. In 1973, the JINR team proposed the name bohrium, after physicist Niels Bohr, later changing their proposal to nielsbohrium to avoid confusion with boron.
Meanwhile, an American team at the Lawrence Radiation Laboratory independently created element 105 at about the same time. They published their discovery in 1970, proposing the element be named hahnium, after the chemist Otto Hahn who had recently passed away.
That’s were things stood until the collapse of the Soviet Union and the end of the Cold War in the 1990s. Element 104 was called either kurchatovium or rutherfordium and 105 either nielsbohrium or hahnium. But the problem of the names would not be resolved easily and would become even more confusing in the 1990s.
In 1994 IUPAC attempted to end the naming controversy, proposing the following naming scheme for elements 101–09:
104: dubnium
105: joliotium (after Frédéic Joliet-Curie)
106: rutherfordium
108: hahnium
This proposal pleased no one, especially the Americans because their proposal for element 106, seaborgium, was dropped because its proposed namesake, chemist Glenn Seaborg, was still living, and the IUPAC decided that element should not be named for living persons.
The controversy dragged on for three more years, until in 1997 the IUPAC came up with a proposal that was acceptable to all (names altered from the 1994 proposal are in bold):
101: mendelevium
102: nobelium
103: lawrencium
104: rutherfordium (née kurchatovium and dubnium)
105: dubnium (née hahnium, bohrium, and nielsbohrium)
106: seaborgium (née joliotium)
107: bohrium (née nielsbohrium)
108: hassium (née hahnium)
109: meitnerium
The names the names hahnium, kurchatovium, and joliotium were dropped. Perhaps these names will be revived if heavier elements are created.
Sources:
Browne, Malcolm W. “Element Is Stripped of Its Namesake.” New York Times, 11 October 1994, C12. ProQuest Historical Newspapers.
Flerov, G.N., et al. “On the Synthesis of Element 105.” Nuclear Physics A, 160.1, January 1971, 181–92.
Flerov, G.N. et al. “Synthesis and Physical Identification of the Isotope with Mass Number 260 of Element 104.” Atomnaya Énergiya, 17.4, October 1964, 1046–48. English translation at SpringerLink Historical Archives Physics and Astronomy. DOI: 10.1007/BF01116295.
Ghiorso, A., et al. “261Rf; New Isotope of Element 104.” Physics Letters B, 32.2, 8 June 1970, 95–98. DOI: 10.1016/0370-2693(70)90595-2.
Ghiorso, Albert, et al. “New Element Hahnium, Atomic Number 105.” Physical Review Letters, 24.26, 29 June 1970, 1498–1503.
International Union of Pure and Applied Chemistry (IUPAC). “Names and Symbols of Transfermium Elements (IUPAC Recommendations 1997).” Pure and Applied Chemistry, 69.12, 1997, 2471–73.
Miśkowiec, Pawel. “Name Game: The Naming History of the Chemical Elements—Part 3—Rivalry of Scientists in the Twentieth and Twenty-First Centuries.” Foundations of Chemistry, 12 November 2022.
Oxford English Dictionary, third edition, March 2012, s.v. dubnium, n., March 2011, s.v. rutherfordium, n.; second edition, 1989, s.v. hahnium, n., kurchatovium, n.
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