Seaborgium (106Sg-266) has several chemical and physical properties similar (homologous)to molybdenum (42Mo-96) and tungsten (74W-184), the elements located just above seaborgiumin group 6 (VIB). Scientists do not know why Sg has properties and characteristicssimilar to the elements above it in group 6. This factor seems odd considering that the twoelements in the transactinide series preceding seaborgium (104Rf-261 and 105Db-262) do nothave homologues above them in groups 4 ad 5. Seaborgium-266 is the most stable isotopeof seaborgium. It has a half-life of 21 seconds and decays into rutherfordium-262 throughspontaneour fission (SF) and alpha emission. The melting point, boiling point, and density of seaborgium are unknown. What is knownis that its isotopes are radioactive metals with short half-lives and that these isotopes decay byfission and alpha emissions.
Isotopes
There a total of 16 isotopes of unnilhexium (seaborgium) with half-lives rangingfrom 2.9 milliseconds to 22 seconds. All are artificially produced and radioactive, andthey decay by spontaneous fission (SF) or alpha decay.
Origin of Name
Named after and in honor of the nuclear chemist Glenn T. Seaborg.
역사
The discovery
of Seaborgium, Element 106, took place in 1974 almost
simultaneously at the Lawrence-Berkeley Laboratory and at
the Joint Institute for Nuclear Research at Dubna, Russia. The
Berkeley Group, under direction of Ghiorso, used the Super-Heavy Ion Linear Accelerator (Super HILAC) as a source of
heavy 18O ions to bombard a 259-μg target of 249Cf. This resulted
in the production and positive identification of 263106,
which decayed with a half-life of 0.9 ± 0.2 s by the emission of
alpha particles.
The Dubna Team, directed by Flerov and Organessian, produced
heavy ions of 54Cr with their 310-cm heavy-ion cyclotron
to bombard 207Pb and 208Pb and found a product that
decayed with a half-life of 7 ms. They assigned 259106 to this
isotope. It is now thought seven isotopes of Seaborgium have
been identified. Two of the isotopes are believed to have halflives
of about 30 s. Seaborgium most likely would have properties
resembling tungsten. The IUPAC adopted the name
Seaborgium in August 1997. Normally the naming of an element
is not given until after the death of the person for which
the element is named; however, in this case, it was named
while Dr. Seaborg was still alive.
용도
None except for research purposes.
정의
seaborgium: Symbol Sg. A radioactivetransactinide element; a.n.106. It was first detected in 1974 byAlbert Ghiorso and a team in California.It can be produced by bombardingcalifornium-249 nuclei withoxygen-18 nuclei. It is named afterthe US physicist Glenn Seaborg(1912–99).
위험도
The hazards for seaborgium are the same as for any radioactive isotopes, but since only afew short-lived atoms are produced, there is no danger to the public.
