Thulium vs Curium

PropertyTm ThuliumCm Curium
Atomic number6996
SymbolTmCm
NameThuliumCurium
Categorylanthanideactinide
Standard Atomic Weight168.93422 u247 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f13[Rn]7s25f76d1
Oxidation states[0, 1, 2, 3][3, 4, 5, 6]
Electronegativity (Pauling)1.251.3
Electron affinity1.029 eV0.277 eV
Density9320 kg/m³1.351000e+4 kg/m³
Melting point1544.85 °C1344.85 °C
Boiling point1949.85 °C3126.85 °C
Discovery year18791944