Iridium vs Curium

PropertyIr IridiumCm Curium
Atomic number7796
SymbolIrCm
NameIridiumCurium
Categorytransition-metalactinide
Standard Atomic Weight192.217 u247 u
Period67
Group9N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f145d7[Rn]7s25f76d1
Oxidation states[-3, -2, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9][3, 4, 5, 6]
Electronegativity (Pauling)2.21.3
Electron affinity1.565 eV0.277 eV
Density2.256220e+4 kg/m³1.351000e+4 kg/m³
Melting point2445.85 °C1344.85 °C
Boiling point4427.85 °C3126.85 °C
Discovery year18031944