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Ununseptium - Ununoctium

Full table
Predicted properties
Name, Symbol, NumberUnunoctium, Uuo, 118
Chemical seriesPresumably noble gases
Group, Period, Block18, 7 , p
Appearance Unknown, probably colourless
Atomic weight [293] amu(A Guess)
Electron configuration [Rn] 5f14 6d10 7s27p6
(a guess based upon radon)
e- 's per energy level2, 8, 18, 32, 32, 18, 8
State of matter presumably a gas
Ununoctium is the temporary name of an undiscovered chemical element in the periodic table that has the temporary symbol Uuo and has the atomic number 118.


In 1999, researchers at Lawrence Berkeley National Laboratory announced the discovery of elements 116 and 118, 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 principal author Victor Ninov.

The name Ununoctium is used as a placeholder, such as in scientific articles about the search for Element 118; it is Dog Latin "one-one-eight-ium" ("ium" being a standard ending for element names). Such transuranic elements are always artificially produced, and usually end up being named for a scientist or the town of their discovery á la darmstadtium. See Element naming controversy, systematic element name.

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