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113 ununbiumununtriumununquadium


Name, Symbol, Number ununtrium, Uut, 113
Chemical series presumably poor metals
Group, Period, Block 13, 7, p
Appearance unknown, probably silvery
white or metallic gray
Standard atomic weight (293)  g·mol−1
Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p1
(guess based on thallium)
Electrons per shell 2, 8, 18, 32, 32, 18, 3
Phase presumably a solid
CAS registry number 54084-70-7
Selected isotopes
Main article: Isotopes of ununtrium
iso NA half-life DM DE (MeV) DP
284Uut syn 0.48 s

Ununtrium (pronounced /juːˈnʌntriəm/), or eka-thallium, is the temporary name of a synthetic element in the periodic table that has the temporary symbol Uut and has the atomic number 113. It comes from the alpha decay (release of a helium nucleus) of ununpentium. Following periodic trends it is expected to be a soft, silvery highly reactive metal, rather like sodium.



On February 1, 2004, the discovery of ununtrium and ununpentium were reported by a team composed of Russian scientists at Dubna (Joint Institute for Nuclear Research), and American scientists at the Lawrence Livermore National Laboratory.

On September 28, 2004, a team of Japanese scientists at RIKEN declared that they succeeded in synthesizing the element.[1][2]

In May 2006, at the Joint Institute for Nuclear Research, the synthesis of this element was confirmed by another method (the chemical identifying on final products of decay of element).


Ununtrium is a temporary IUPAC systematic element name. Scientists from Japan proposed for the element the name japonium (symbol Jp) or rikenium (Rk) after RIKEN.[3]

See also


  1. ^ Morita et al, Experiment on the Synthesis of Element 113 in the Reaction 209Bi(70Zn, n)278113, J. Phys. Soc. Jpn., Vol. 73, No.10. Also press release in Japanese
  2. ^ [1]
  3. ^ [2]
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Ununtrium". A list of authors is available in Wikipedia.
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