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| Known properties |
| Name, Symbol, Number |
unununium, Uuu, 111 |
| Chemical series |
Transition metals |
| Group, Period, Block |
11, 7 , d |
| Appearance |
unknown; probably metallic,
silvery white or gray |
| Atomic weight |
[272] amu |
| Electron configuration |
probably [Rn]5f14
6d10 7s1 |
| e- 's per energy
level |
2, 8, 18, 32, 32, 18, 1 |
| State of matter |
Presumably a solid |
Unununium (Roentgenium is the proposed name) is a chemical element in the periodic table that has
the symbol Uuu and atomic number 111. It has an atomic weight of 272
making it one of the super-heavy atoms. It is a synthetic
element whose only known isotope has a half-life of around 15 ms before it decays into meitnerium. Due to its presence in Group 11 it is a transition metal and so probably metallic and solid.
History
It was first created at the
Gesellschaft für
Schwerionenforschung (GSI) in Darmstadt, Germany on December 8, 1994. Only three atoms of it have been created (all Uuu-272), by the fusion of
bismuth-209 and nickel-64 in a linear accelerator (nickel was bombarded onto the target).
Unununium is a temporary IUPAC systematic element name. There is an ongoing element naming controversy over what this element should be called.
External links
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