element.nameElectron Panel Modal created by GPPT Lab111Atom NumberRgSymbolRoentgeniumNameTransition metalCategory11.0GroupSolidPhaseDiscovered ByGesellschaft für Schwerionenforschung1994Year282.169uAtomic Mass0.000kJ/molMolar Heat0.00Atomic Radius11.0Groupg/cm328.700Density7.0Period0.000°KBoil-0.001°KMelt
Electrons>element.nameElectron shell created by GPPT Lab contact@gppt.tnRg111
Protons and Neutronselement.nameElectron shell created by GPPT Lab contact@gppt.tn111 neutron111 Proton
Roentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, roentgenium-282, has a half-life of 2.1 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany.