Artificial radioactive element properties unknown	memory peg
	1955 Albert Ghiorso and co-workers, Berkeley, Calif., USA,
	Д. И. Менделеев (D.I. Mendeleyev) (1834-1907)

First prepared in 1955 by Albert Ghiorso, Bernard G. Harvey, Gregory R. Choppin, Stanley G. Thompson, and Glenn T. Seaborg at the Berkeley Laboraty of the University of California by bombardment of Einsteinium with Helium ions.

In his autobiography, Seaborg says about the naming of Mendelevium (note) :

We thought it fitting that there be an element named for the Russian chemist Dmitri Mendeleev, who had developed the periodic table. In nearly all our experiments discovering transuranium elements, we'd depended on his method of predicting chemical properties based on the element's position in the table. But in the middle of the Cold War, naming an element for a Russian was a somewhat bold gesture that did not sit well with some American critics.

Дмитрий Иванович Менделеев (Dmitrij Ivanovič Mendeleyev) (1834-1907), Russian chemist, who framed the periodic law in chemistry, which states that the chemical properties of the elements depend on their relative atomic masses (1869). This law is the basis of the periodic table of elements. With this table the properties of missing elements were forecast, and chemists began to appreciate it when the discovery of elements predicted by the table took place.

In 1980, at the symposium Commemorating the 25th Anniversary of the Discovery of Mendelevium, Glenn T. Seaborg recalls the following anecdote, which was published in the Daily Cal at the time of the discovery of element #101:

"The University of California Nuclear Metaphysical Laboratories have announced a startling new finding in the world of atomics. The new discovery is an entirely novel element named 'Percentium' by its discoverer, the 15 1/2 year old Leonardo da Vinci. The element, number 101 in the atomic series, follows element number 100, 'Centium.' The youthful da Vinci said that this was the reason for the new element's name, Percentium. 'The interesting fact about Percentium,' said Moosbrugger, 'is that it has a negative half-life. That is,' he went on, 'its radioactivity and total mass increase 1 percent every 100 years. Probably it is the first of a series of elements that spontaneously integrates the successive members of the series.'" (this is not all, read the pdf-file, available on-line).

John and Gordon Marks suggested in 1994 the name Bohemium (Bo) after Bohemia, where the actinides were first mined, cf. thulium after Thule where the lanthanides were first mined. The Marks brothers found the old names ugly and confusing. They offered alternative names that are equivalent contemporary (at the time and place of discovery) metaphors, both more euphonious and more memorable (note).

Further reading (Mendelevium):

• Earl K. Hyde & Glenn T. Seaborg, Transurane : Teil A 1, I: Die Elemente. Gmelins Handbuch der anorganische Chemie, Ergänzungswerk zur 8. Aufl.; Band 7a. Weinheim/Bergstrasse: Chemie, 1973.
• Glenn T. Seaborg, Early History of LBNL, A transcript of the lecture on the 65th Anniversary of Lawrence Berkeley National Laboratory, August 26, 1996 (on-line).
• A. Ghiorso, B.G. Harvey, G.R. Choppin, S.G. Thompson, and G.T. Seaborg, "New Element Mendelevium, Atomic Number 101" Phys. Rev. 98 (1955), 1518.

Naming the transfermium elements

The Transfermium Working Group was established in 1986 by the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP). The working group published several reports, and then recommended that elements should not be named after living persons. This greatly upset the USA - who wanted to name an element after Glenn T. Seaborg. In 1994 a IUPAC recommandation was made (names marked (1) in the table below). As a result of the criticisms on these names, the commission reconsidered the names at a meeting in August 1996.

"After some discussion CNIC [= IUPAC Commission on Nomenclature in Inorganic Chemistry] agreed that elements 101, 102 and 103 should retain their commonly accepted names mendelevium, nobelium, and lawrencium. This is despite the fact that the original Swedish claim to have prepared element 102 was subsequently shown to have been in error by the Dubna laboratory, which finally achieved an undisputed synthesis. The adjudicate on competing claims for priority of discovery. The Commission hopes that the present collection of names will be accepted as a fair compromise between the various claims and suggestions. It recognizes important experimental and theoretical contributions to the discovery of new elements and also the international discovery of element 106 by the Berkeley laboratory is uncontested and the name proposed by the discoverers, seaborgium, was accepted. The discoveries of elements 107 jointly by the Darmstadt and Dubna laboratories), and of 108 and 109 (by the Darmstadt laboratories) are also uncontested. The discoverers wished to call these nielsbohrium, hassium, and meitnerium, respectively, and the Commission accepted the last two. However, the proposal for 107 was the subject of vigorous debate. The name nielsbohrium is long and includes the first name of Niels Bohr as well as his family name. Such an element name is without precedent. Finally it was decided to refer the matter to the Danish NAO [= National Adhering Organization]. Its preference for bohrium rather than nielsbohrium was ultimately accepted. The discoveries of elements 104 and 105 are contested by Dubna and Berkeley. Both laboratories ap-pear 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. Finally, the Commission accepted the name rutherfordium for element 104, to honour the New Zealand nuclear physicist, Emest Rutherford." (note)

Names of the transfermium elements No. syst. IUPAC (5) IUPAC 1997/IUPAP 1999 proposals 101 Unu Unnilunium Md Mendelevium (2, 5)   102 Unb Unnilbium No Nobelium (2, 5)   103 Unt Unniltrium Lr Lawrencium (2, 5)   104 Unq Unnilquadium Rf Rutherfordium (2) Ku Kurchatovium (3) Db Dubnium (1) 105 Unp Unnilpentium Db Dubnium Ha Hahnium (2) Jo Joliotium (1) Ns Nielsbohrium (3) 106 Unh Unnilhexium Sg Seaborgium (2) Rf Rutherfordium (1) 107 Uns Unnilseptium Bh Bohrium (1) Ns Nielsbohrium (2, 4) 108 Uno Unniloctium Hs Hassium (2, 4) Ha Hahnium (1) 109 Une Unnilenium Mt Meitnerium (2, 4)   (1) IUPAC 1994 recommandations (on-line PDF). (2) American Chemical Society 1994 Proposal. (3) Proposal by the Объединенный Институт Ядерных Исследований (ОИЯИ) - Joint Institute for Nuclear Research (JINR) at Дубна (Dubna), Russia. (4) Proposal (1992) by Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany. (5) Commission on the Nomenclature of Inorganic Chemistry, Recommendations for the Naming of Elements of Atomic Numbers Greater than 100 (Rules Approved 1978). (on-line)

This compromise selection of names was ratified by the IUPAC Council meeting in Geneva during August 1997. The identical list of names was recommended by IUPAP's C2 Commission on Symbols, Units, Nomenclature, Atomic Masses and Constants (SUNAMCO) in its report to the 1999 General Assembly for 1996-99 (note). A joint IUPAP/IUPAC Committee has been set up to consider the discovery of elements 110-112.

Further reading:

• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Heny M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 850-851.
• Peter Gwynne, The Name Game (Scientific teams in three nations took part in a tough competition to create new elements. Then they faced the really difficult step: agreeing on what to call them) (on-line).
• Lynn Yarris, Naming of element 106 disputed by international committee. October 14, 1994 (on-line).
• Sci.chem FAQ, chapter 12 Nomenclature (on-line)