Curium vs Roentgenium

PropertyCm CuriumRg Roentgenium
Atomic number96111
SymbolCmRg
NameCuriumRoentgenium
Categoryactinidetransition-metal
Standard Atomic Weight247 u281 u
Period77
GroupN/A11
Blockss
Phase at STPsolidN/A
Electron configuration[Rn]7s25f76d1[Rn] 7s2 5f14 6d9(predicted)
Oxidation states[3, 4, 5, 6][-1, 1, 3, 5]
Electronegativity (Pauling)1.3N/A
Electron affinity0.277 eV1.6 eV
Density1.351000e+4 kg/m³2.870000e+4 kg/m³
Melting point1344.85 °C-273.15 °C
Boiling point3126.85 °C-273.15 °C
Discovery year19441994