Periodic Table


Atomic number: 110
Atomic weight: 269
Symbol: Uun
Group number: 10
Electronic configuration: [Rn].5f14.6d9.7s1 (a guess based upon that of platinum)


Element 110, ununnilium, is a synthetic element that is not present in the environment at all. Further information on element 110 is here (outside WebElements) and in a press release (outside WebElements). The interested reader should consult the on-line version of The Wonderful World of Atoms and Nuclei for a fascinating insight into research on "super-heavy" atoms.

Chemically, the element 110 is in the same Group as nickel, palladium, and platinum (Group 10). Unlike these lighter atoms, element 110 decays after a small fraction of a thousandth of a second into lighter elements by emitting a-particles which are the nuclei of helium atoms.

General information

Discoveror: S. Hofmann, V. Ninov, F. P. Hessberger, P. Armbruster, H. Folger, G. Münzenberg, H. J. Schött, and others
Date discovered: 1994
Discovered at: Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany.
Meaning of name: Temporary IUPAC nomenclature

Physical data

Standard state: unknown but presumably a solid at 298 K
Colour: py


This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Uun.html