Californium vs Roentgenium

PropertyCf CaliforniumRg Roentgenium
Atomic number98111
SymbolCfRg
NameCaliforniumRoentgenium
Categoryactinidetransition-metal
Standard Atomic Weight251 u281 u
Period77
GroupN/A11
Blockss
Phase at STPsolidN/A
Electron configuration[Rn]7s25f10[Rn] 7s2 5f14 6d9(predicted)
Oxidation states[2, 3, 4, 5][-1, 1, 3, 5]
Electronegativity (Pauling)1.3N/A
Electron affinity-0.5 eV1.6 eV
Density1.510000e+4 kg/m³2.870000e+4 kg/m³
Melting point899.85 °C-273.15 °C
Boiling point-273.15 °C-273.15 °C
Discovery year19501994