Francium vs Curium

PropertyFr FranciumCm Curium
Atomic number8796
SymbolFrCm
NameFranciumCurium
Categoryalkali-metalactinide
Standard Atomic Weight223 u247 u
Period77
Group1N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s1[Rn]7s25f76d1
Oxidation states[1][3, 4, 5, 6]
Electronegativity (Pauling)0.71.3
Electron affinity0.491 eV0.277 eV
Density1870 kg/m³1.351000e+4 kg/m³
Melting point26.85 °C1344.85 °C
Boiling point-273.15 °C3126.85 °C
Discovery year19391944