Roentgenium

Atomic Number:111Atomic Radius:empirical: 138 pm (predicted)[2][4]
Atomic Symbol:RgMelting Point:
Atomic Weight:282Boiling Point:
Electron Configuration:[Rn] 7s2 5f14 6d9(predicted)[1][2]Oxidation States:5, 3, 1, −1 ​(predicted)[2][4]

History

Discovered by Gesellschaft Schwerionenforschung (GSI) in Darmstadt, in 1994. Reasearch group of S. Hofmann, V. Ninov, F.P. Hessberger, P. Armbruster, H. Folger, G. Munzenberg, H.J. Schott, and others.