Stable isotope Roentgenium (Rg)

Isotope Atomic Mass Half-life Mode of Decay
Rg-272 272.1535 0.0015 seconds α to Mt-268
Rg-279 279 0.17 seconds α to Mt-275
Rg-280 280 3.60 seconds α to Mt-276

Properties of Roentgenium

Name Roentgenium
Symbol Rg
Atomic number 111
Atomic weight [280]
Standard state Presumably a solid at 298 °K
CAS Registry ID 54386-24-2
Group in periodic table 11
Group name None
Period in periodic table 7
Block in periodic table d-block
Color Unknown, but probably metallic and silvery white or grey in appearance
Melting point No data available
Boiling point No data available
Density of solid 28.7 g/cm3 (predicted)
Electron configuration [Rn]5f146d97s2