Unununium

darmstadtium - unununium - ununbium Au Uuu         Full table
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]55f14 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

Unununium is a temporary IUPAC systematic element name. There is an ongoing element naming controversy over what this element should be called. The name roentgenium has been proposed.

External links

• WebElements.com - Unununium
• IUPAC: Proposal of name roentgenium for element 111
• Apsidium - Roentgenium Element 111