Atomic and nuclear properties of materials:
Roentgenium (Rg)

Quantity	Value	Units
Atomic number	111	n
Atomic mass	(272.1536)	g mole-1
Density (20° C, 1 atm):	Unknown	g cm-3
Radiation length	Pending	g cm-2
Nuclear collision length	Pending	g cm-2
Nuclear interaction length	Pending	g cm-2
Critical energy (e-)	Pending	MeV
Molière radius	Pending	g cm-2
Muon critical energy	Pending	GeV

Explanation of some entries
As of 2004, element 111 is officially named Roentgenium
(Pure Appl. Chem. 76(12), 2101-2103, 2004).
Table of isotopes