Atomic number: 106
Year discovered: 1974
Discovered by: Albert Ghiorso (born July 15, 1915) and co-workers at the Lawrence Berkeley Laboratory in California and the Livermore National Laboratory, USA.
- It is the first time an element has been named for a living person.
- This element was once named, unnilhexium; Symbol: Unh; which is the Latin equivalent for the number "106".
- Transuranium elements such as seaborgium can be created artificially in particle accelerators.
- Isotopes of seaborgium have short half-lives of less than a second.
- The first report of element 106 came in 1974 from the Soviet Joint Institute for Nuclear Research and these were followed later by others from Berkeley in California, USA.
- Experiments at the same American institution confirmed the discovery in 1993.
- The naming of a chemical element is influenced by national pride, professional rivalry and personal sensitivities; the picking of a single name can provoke as much back-room bickering and bargaining as the selection of the head of the United Nations.
- The final court of appeals in this process is the International Union of Pure and Applied Chemistry (IUPAC), with member chemists from about 80 countries.
- Within the Union, factions representing the United States, Germany, Russia and several other nations have bitterly disagreed about names.
- A particularly sharp disagreement began when the Lawrence Berkeley Laboratory in Berkeley, California, backed by the American Chemical Society, tentatively named element 106, seaborgium, with the chemical symbol Sg.
- The name honored Glenn T. Seaborg, an American chemist and Nobel laureate, whose team created 10 new elements during and after World War II.
- In 1940, Seaborg’s research group at Berkeley used an accelerator to make neptunium, the first element heavier than uranium.
- Before neptunium, the only element existing solely as a laboratory product was technetium, which is No. 43 on the periodic table. It was created in 1937 by the fusion of atomic nuclei.
- Seaborg’s team went on to create plutonium, the element fueling the atomic bomb that destroyed Nagasaki, and eight other artificial elements.
- The American Chemical Society believed that international confirmation of the name seaborgium would be mere formality, but instead the international chemists’ union provisionally named Element 106 rutherfordium honoring New Zealand-born physicist Ernest Rutherford.
- Adding insult to injury, in the view of the Berkeley group, the international union proposed naming element 104, “dubnium”, recognizing achievements in nuclear physics by the Joint Institute for Nuclear Research at Dubna, Russia.
- The Berkeley scientists and many other American physicists were skeptical of some of the claims made by the Dubna laboratory to having created new elements.
- After years of debate, the international union in January, 1997, came up with a compromise list that most American chemists deemed acceptable.
- David F. Eaton, a chemist at DuPont Corporation, who headed the American delegation throughout the bargaining, said in an interview that all of the American laboratories involved in the dispute were satisfied.
- The union’s members at a meeting in Geneva in August, 1997, confirmed the following as the names of the six new elements: Element 104, rutherfordium (symbol Rf); Element 105, dubnium (symbol Db); Element 106, seaborgium (symbol Sg); Element 107, bohrium (symbol Bh); Element 108, hassium (symbol Hs).
- Bohrium takes its name from Niels Bohr, a Dane, who was a founder of quantum physics.
- Hassium is the Latin name for the German province Hessen, the seat of the laboratory where elements 109 and 110 were created, as well as a single atom of element 112 in 1996.
- Meitnerium is named for the Austrian-born physicist Lise Meitner.
- Dropped from the union’s previous list of provisional names were “joliotium” for Element 105, for the French physicist Frédéric Joliet-Curie, and “hahnium” for Element 108, honoring the German physicist Otto Hahn.
- As far as naming element 106, seaborgium, the following will expand on this rare honor to, at the time of the naming, a living recipient.
- “This is the greatest honor ever bestowed upon me—even better, I think, than winning the Nobel Prize,” said Seaborg, the co-discoverer of plutonium and nine other transuranium elements.
- “Future students of chemistry, in learning about the periodic table, may have reason to ask why the element was named for me, and thereby learn more about my work.”
- Seaborgium has a half-life of less than a second. It was first created and identified in 1974 in an experiment conducted at LBL (Lawrence Berkeley Laboratory) by a team of LBL and LNL (Livermore National Laboratory) researchers led by Hulet and LBL physicist Albert Ghiorso.
- According to criteria proposed by nuclear science researchers in the 1970’s, the naming of a new element is the prerogative of the original discovery team, but proposal of a name should await independent confirmation of the discovery.
- Seaborgium was finally confirmed in 1993 in an experiment at LBL’s 88-Inch Cyclotron that was designed by Ken Gregorich, a divisional fellow in LBL’s Nuclear Science Division, and carried out by a team including Gregorich and LBL faculty senior scientist Darleane Hofmann, plus postdoctoral fellows and students from LBL and the UC Berkeley Department of Chemistry.
- Born in 1912 in Ishpeming, Michigan, Seaborg received a Ph.D. in chemistry from UC Berkeley in 1937.
- He joined the UCB faculty in 1939 and served as chancellor from 1958 to 1961.
- From 1961 through 1971, Seaborg served as chairman of the Atomic Energy Commission (predecessor of the U.S. Department of Energy) under U.S. Presidents Kennedy, Johnson, and Nixon.
- He then returned to research at Berkeley, where he continued until 1998 in his search for new elements and isotopes.
- In addition to his duties at LBL, Seaborg was a University Professor (UC’s highest academic position), and chairman of the Lawrence Hall of Science.
- Seaborg was perhaps best known for his role in the discovery of plutonium.
- This took place in 1940, when Seaborg, McMillan, Joseph Kennedy, and Arthur Wahl, using the 60-inch cyclotron built by Ernest Lawrence, bombarded a sample of uranium with deuterons and transmuted it into plutonium.
- Seaborg and his co-workers used the discovery of plutonium as a stepping stone to the creation of a succession of transuranium elements—americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and then seaborgium.
- Seaborg held more than 40 patents, including the only ones for chemical elements (americium and curium).
- He was the author of numerous books and more than 500 scientific articles.
- He has been awarded 50 honorary doctoral degrees and was recognized as a national advocate for science and math education.
In the March 1, 1999, issue of The International Herald Tribune, is the announcement: “Glenn Seaborg, 86, U. S. Physicist Who Created Plutonium, Dies”.
- The article goes on to say that Glenn Seaborg, 86, “died Thursday [February 25] at his home in Lafayette, California, following complications of a stroke he suffered in August while exercising on a flight of stairs”.
- Although he was a chemist by training and occupation, Mr. Seaborg became one of the best known nuclear physicists in history.
- He led the research that created nine artificial elements, all heavier than uranium. They were plutonium, americium (used today in smoke detectors), curium (used in medicine), berkelium, californium, einsteinium, fermium, mendelevium and nobelium.
- Two years ago (1997) Element 106, which Mr. Seaborg did not create or discover, was formally named seaborgium in his honor.
- Until then, no element had been named after a living person.
Name in other languages:
Information about other elements may be seen at this Chemical Elements List.
A special unit about words that include chemo-, chem- may be seen here.