unnilhexium definition of unnilhexium in the Free Online Encyclopedia.

seaborgium (sēbôr`gēəm), artificially produced radioactive chemical element; symbol Sg; at. no. 106; mass number of most stable isotope 266; m.p., b.p., sp. gr., and valence unknown. Situated in Group 6 of the periodic table periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley . In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the
..... Click the link for more information. , it is expected to have properties similar to those of tungsten tungsten (tŭng`stən) [Swed.,=heavy stone], metallic chemical element; symbol W; at. no. 74; at. wt. 183.85; m.p.
..... Click the link for more information. .

The discovery of element 106 took place almost simultaneously in two different laboratories. In June, 1974, a Soviet team led by G. N. Flerov at the Joint Institute for Nuclear Research at Dubna reported bombarding lead-207 and lead-208 atoms with chromium-54 ions to produce an isotope with mass number 259 and a half-life half-life, measure of the average lifetime of a radioactive substance (see radioactivity ) or an unstable subatomic particle. One half-life is the time required for one half of any given quantity of the substance to decay.
..... Click the link for more information. of 7 msec. In Sept., 1974, an American research team led by A. Ghiorso at the Lawrence Berkeley National Laboratory reported bombarding californium-249 atoms with oxygen-18 ions to create an isotope with mass number 263 and a half-life of 0.9 sec. Because their work was independently confirmed first, the Americans suggested the name seaborgium to honor the American chemist Glenn T. Seaborg Seaborg, Glenn Theodore (sē`bôrg), 1912–99, American chemist, b. Ishpeming, Mich., grad. Univ.
..... Click the link for more information. . An international committee decided in 1992 that the Berkeley and Dubna laboratories should share credit for the discovery. The syntheses of at least six isotopes of seaborgium, with half-lives ranging from 0.4 msec (Sg-260) to 30 sec (Sg-266), have been confirmed.

In 1994 a committee of the International Union of Pure and Applied Chemistry (IUPAC), convened to resolve naming disputes for the transactinide elements transactinide elements (trăns'ăk`tənīd'), in chemistry, elements with atomic numbers greater than that of lawrencium (at.
..... Click the link for more information. , recommended that element 106 be named rutherfordium rutherfordium (rŭth'ərfôr`dēəm), artificially produced radioactive chemical element; symbol Rf; at. no.
..... Click the link for more information. . In 1997, however, the name seaborgium for element 106 was recognized internationally.

See also synthetic elements synthetic elements, in chemistry, radioactive elements that were not discovered occurring in nature but as artificially produced isotopes. They are technetium (at. no. 43), which was the first element to be synthesized, promethium (at. no. 61), astatine (at. no.
..... Click the link for more information. ; transuranium elements transuranium elements, in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as synthetic radioactive isotopes at the Univ.
..... Click the link for more information. .

seaborgium

a synthetic transuranic element, synthesized and identified in 1974. Symbol: Sg; atomic no.: 106

seaborgium (redirected from unnilhexium)

seaborgium
(redirected from unnilhexium)