Roentgenium - Rg General Information Discovery Hofmann and co-workers in 1994 in Darmstadt, Germany. Name officially approved by IUPAC in 2004. Appearance Not known, since only a few atoms have been made and it decays rapidly. Since it is in the same group as Copper, Silver and Gold, it is probably a metal which is solid at room temperature. Source Fusion-evaporation using a 64Ni beam on a 209Bi target, which produced a total of six decay chains of alpha-emitting nuclides following the presumed formation of 272Rg + n 20983Bi + 6428Ni --> 272111Rg + 10n Uses None at present since only a few atoms have been made. Biological Role Roentgenium has no known biological role. It is toxic due to its radioactivity. General Information Roentgenium was produced by fusing a bismuth and a nickel atom together in a heavy ion accelerator. Roentgenium decays in 0.15 milliseconds into Meitnerium by emitting alpha-particles.

	Physical Information
	Atomic Number		111
	Relative Atomic Mass (12C=12.000)		272
	Melting Point/K		Not known
	Boiling Point/K		Not known
	Density/kg m-3		Not known
	Ground State Electron Configuration		Not known, but based on gold, perhaps  [Rn]5f146d107s1
	Electron Affinity(M-M-)/kJ mol-1		Not known

	Key Isotopes
	nuclide	272Rg
	atomic mass
	natural abundance	0%
	half-life	0.15 ms

Other Information
Enthalpy of Fusion/kJ mol-1		Not known
Enthalpy of Vaporisation/kJ mol-1		Not known
Oxidation States
	Not known

	Ionisation Energies/kJ mol-1
	M - M+	Not known
	M+ - M2+	Not known
	M2+ - M3+	Not known
	M3+ - M4+	Not known
	M4+ - M5+	Not known
	M5+ - M6+	Not known
	M6+ - M7+	Not known
	M7+ - M8+	Not known
	M8+ - M9+	Not known
	M9+ - M10+	Not known