Terbium vs Curium

PropertyTb TerbiumCm Curium
Atomic number6596
SymbolTbCm
NameTerbiumCurium
Categorylanthanideactinide
Standard Atomic Weight158.92535 u247 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f9[Rn]7s25f76d1
Oxidation states[0, 1, 2, 3, 4][3, 4, 5, 6]
Electronegativity (Pauling)N/A1.3
Electron affinity1.124 eV0.277 eV
Density8230 kg/m³1.351000e+4 kg/m³
Melting point1355.85 °C1344.85 °C
Boiling point3229.85 °C3126.85 °C
Discovery year18431944