Roentgenium

Symbol: Rg
Atomic number: 111
Category: transition metals
Group: 11
Period: 7
Block: d
Atomic weight: [280] g/mol
Electrons per shell: 2, 8, 18, 32, 32, 17, 2
CAS number: 54386-24-2
Phase: presumably a solid
Density: unknown
Melting point: unknown
Boiling point: unknown
Crystal structure: unknown
Oxidation states: 3 (expected)
Electronegativity: unknown
Name's origin: Röntgen
Name's meaning: the German physicist Wilhelm Conrad Röntgen
Facts:
- is a synthetic element
- its most stable known isotope has a mass of 283 amu and an estimated half-life of ten minutes
- was found by Peter Armbruster, Gottfried Münzenberg, and their team working at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany on December 8, 1994, but the IUPAC/IUPAP Joint Working Party (JWP) concluded that there was insufficient evidence for the discovery at that time
- the GSI team repeated their experiment in 2000 and detected a further 3 atoms, and in their 2003 report, the JWP decided that the GSI team should be acknowledged as the discoverers