Curium vs Berkelium

PropertyCm CuriumBk Berkelium
Atomic number9697
SymbolCmBk
NameCuriumBerkelium
Categoryactinideactinide
Standard Atomic Weight247 u247 u
Period77
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s25f76d1[Rn]7s25f9
Oxidation states[3, 4, 5, 6][2, 3, 4, 5]
Electronegativity (Pauling)1.31.3
Electron affinity0.277 eV-0.5 eV
Density1.351000e+4 kg/m³1.400000e+4 kg/m³
Melting point1344.85 °C1049.85 °C
Boiling point3126.85 °C-273.15 °C
Discovery year19441949