116
  Uuh  
289.000000
Unuhexium

Name: Unuhexium
Symbol: Uuh
Atomic Number: 116
AtomicWeight: 289.000000
Family: Other Metals
CAS RN: 54100-71-9
Description: A very short lived super heavy element, appearance unknown, probably metallic solid
State (25C): Unknown (Synthetic)
Oxidation states:
Valence Electrons: 5f146d107s27p4

Boiling Point:  unknown
Melting Point:
unknown
Electrons Energy Level: unknown
Isotopes: 5 + None Stable
Heat of Vaporization: unknown
Heat of Fusion: unknown
Density: unknown
Specific Heat: unknown
Atomic Radius: unknown
Ionic Radius: unknown
Electronegativity: unknown
Ununhexium is the temporary IUPAC systematic name of a synthetic superheavy element in the periodic table that has the temporary symbol Uuh and has the atomic number 116. Some research has referred to it as "Eka-Polonium".

In 1999, researchers at Lawrence Berkeley National Laboratory announced the discovery of elements 116 and 118 (Ununhexium and Ununoctium), in a paper published in Physical Review Letters.  The following year, they published a retraction after other researchers were unable to duplicate the results.  In June 2002, the director of the lab announced that the original claim of the discovery of these two elements had been based on data fabricated by the principal author Victor Ninov.

Results published on the 6th December 2000 concerning experiments at Dubna in Russia (involving workers from The Joint Institute for Nuclear Research, Dubna, Russian Federation; U.S. Department of Energy's Lawrence Livermore National Laboratory, California, USA; The Research Institute of Atomic Reactors, Dimitrovgrad, Russian Federation; and The State Enterprise Electrohimpribor, Lesnoy, Russian Federation) describe the decay of the isotope 292Uuh.  They produced Ununhexium by bombarding atoms of Curium-248 with ions of Calcium-48.  This produced Ununhexium-292, an isotope with a half-life of about 0.6 milliseconds (0.0006 seconds), and four free neutrons.

8
O
15.99
16
S
32.06
34
Se
78.96
52
Te
127.6
84
Po
210.0
116
Uuh
289.0

ununhexium1.jpg (4334 bytes)

An isotope of Element 116 (292Uuh) was identified in the reaction of 248Cm with 48Ca (shown above).  It is very shortlived (47 milliseconds) and decomposes to a previously identified isotope of element 114, 288114Uuq.

ununhexium2.jpg (3669 bytes)

Various reports indicated the half-life of 292Uuh as being 47 milliseconds,  0.6 milliseconds (0.0006 seconds, and 18 milliseconds (0.018 seconds.

1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f14
6s2 6p6 6d10
7s2 7p4

On May 11, 2001, the institute reported synthesizing a second atom, and that the properties confirmed a region of "enhanced" stability.

In 2004 in the Joint Intitute for Nuclear Research the synthesis of this element was confirmed by another method.

In October, 2006 it was announced that on three occasions Californium-249 atoms had been bombarded with Calcium-48 ions to produce Ununoctium-118, which decayed to Ununhexium within a millisecond.  If confirmed, the synthesis of element 116 will have been proven definitively.

Other sources report the following:

Ununhexium's most stable isotope, Ununhexium-291, has a half-life of about 18 milliseconds. It decays into Ununquadium-287 through alpha decay.

Since only a few atoms of Ununhexium have ever been produced, it currently has no uses outside of basic scientific research.

atom.gif (700 bytes)

Isotope  
Atomic Mass
 
Half-Life
289Uuh 289.19886 ~10 ms
290Uuh 290.19859 15 ms
291Uuh 291.20001 6.3 ms
292Uuh 292.19979 18.0 ms
293Uuh   61 ms

Interactive Periodic Table