Gadolinium vs Actinium

PropertyGd GadoliniumAc Actinium
Atomic number6489
SymbolGdAc
NameGadoliniumActinium
Categorylanthanideactinide
Standard Atomic Weight157.25 u227 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f75d1[Rn]7s26d1
Oxidation states[0, 1, 2, 3][3]
Electronegativity (Pauling)1.21.1
Electron affinity0.132 eV0.35 eV
Density7900 kg/m³1.007000e+4 kg/m³
Melting point1312.85 °C1050.85 °C
Boiling point3272.85 °C3197.85 °C
Discovery year18861899