Elements 102–109: The History and Controversy of Superheavy Element Naming
The discovery of the superheavy elements between atomic numbers 102 and 109 was not merely a scientific triumph but a diplomatic challenge. For years, a naming controversy persisted as different nations and research institutions claimed priority and proposed different names for these new additions to the periodic table. To resolve these disputes, the International Union of Pure and Applied Chemistry (IUPAC)—the global authority on chemical nomenclature—stepped in to standardize the names and implement a temporary systematic naming convention to maintain order during the deliberation process.
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Key Facts
- IUPAC eventually resolved naming disputes for elements 102 through 109, adopting a single official name for each.
- Systematic names (such as unnilhexium) were used as temporary placeholders before permanent names were ratified.
- Seaborgium (106) sparked significant debate because it was named after a living person, Glenn T. Seaborg.
- Geographic honors are present in the naming of Dubnium (after Dubna, Russia) and Hassium (after Hesse, Germany).
- Scientific pioneers like Alfred Nobel, Ernest Lawrence, and Lise Meitner are honored among these elements.
The Journey from Element 102 to 105
The early part of this series saw relatively straightforward ratifications, though some were influenced by the preferences of national chemical societies.
Nobelium (102) and Lawrencium (103)
Element 102 was named nobelium (No) in honor of Alfred Nobel. Element 103 was named lawrencium (Lr) after Ernest Lawrence; this specific name was preferred by the American Chemical Society and ratified by IUPAC during a meeting in Geneva.
Rutherfordium (104) and Dubnium (105)
Naming became more contentious with element 104. The Joint Institute for Nuclear Research in Dubna (USSR/Russia) proposed kurchatovium (Ku) for Igor Kurchatov, while the University of California, Berkeley, proposed rutherfordium (Rf) for Ernest Rutherford. In 1997, IUPAC recommended rutherfordium.
Similarly, element 105 saw a clash between the proposal of nielsbohrium (Ns) from Dubna and hahnium (Ha) from Berkeley. IUPAC ultimately chose dubnium (Db), naming the element after the city of Dubna.
The Seaborgium Conflict and Element 106
Element 106 represents one of the most complex naming battles in chemistry. Discovered almost simultaneously in 1974 by a Soviet team led by G. N. Flyorov and an American team led by Albert Ghiorso, the discovery credit was eventually shared in 1992.
The Americans proposed seaborgium (Sg) for Glenn T. Seaborg. This was highly controversial because Seaborg was still alive. In 1994, IUPAC established a rule that no element could be named after a living person, a move fiercely opposed by the American Chemical Society. Proponents of the name pointed to einsteinium (Es) and fermium (Fm), which were named during the lives of Albert Einstein and Enrico Fermi (though not publicly announced until after their deaths). A compromise was reached in 1997, and seaborgium was internationally recognized.
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Finalizing the Series: Elements 107 to 109
The final three elements of this group were settled through a mix of linguistic caution and geographic recognition.
Bohrium (107)
Element 107 was named bohrium (Bh) in honor of Niels Bohr. While some suggested "nielsbohrium," IUPAC opted for the surname only. This caused concern among some scientists who feared it would be confused with boron (called borium in Latin and other languages), but the name was ratified in 1997.
Hassium (108) and Meitnerium (109)
Element 108 was named hassium (Hs) after the German state of Hesse (Hassia in Latin), which encompasses Darmstadt, the site of the GSI Helmholtz Centre for Heavy Ion Research. Element 109 was named meitnerium (Mt) in honor of Lise Meitner; this was the only proposal for the element and faced no dispute.
Summary of Element Naming and Proposals
| Element | Systematic Name | Final IUPAC Name | Honoree/Origin |
|---|---|---|---|
| 102 | Unnilbium | Nobelium | Alfred Nobel |
| 103 | Unniltrium | Lawrencium | Ernest Lawrence |
| 104 | Unnilquadium | Rutherfordium | Ernest Rutherford |
| 105 | Unnilpentium | Dubnium | Dubna, Russia |
| 106 | Unnilhexium | Seaborgium | Glenn T. Seaborg |
| 107 | Unnilseptium | Bohrium | Niels Bohr |
| 108 | Unniloctium | Hassium | Hesse, Germany |
| 109 | Unnilennium | Meitnerium | Lise Meitner |
Frequently Asked Questions
Why were temporary names like "unnilhexium" used?
Temporary systematic names were adopted by IUPAC to provide a consistent way to refer to new elements while international committees resolved disputes over permanent names.
Why was the naming of Seaborgium so controversial?
It was controversial because Glenn T. Seaborg was alive at the time the name was proposed, and IUPAC had a rule stating that elements should not be named after living persons.
What is the difference between Bohrium and Boron?
Bohrium (element 107) is a synthetic superheavy element named after Niels Bohr, whereas Boron is a naturally occurring metalloid. The names were noted as potentially confusing because Boron is called "borium" in some languages.
Which elements were named after locations rather than people?
Dubnium (105) was named after the city of Dubna in Russia, and Hassium (108) was named after the German state of Hesse.
How was the dispute over element 104 resolved?
After competing proposals for "kurchatovium" (Russia) and "rutherfordium" (USA), an IUPAC committee recommended the name rutherfordium in 1997.