Gadolinium vs Polonium

PropertyGd GadoliniumPo Polonium
Atomic number6484
SymbolGdPo
NameGadoliniumPolonium
Categorylanthanidemetalloid
Standard Atomic Weight157.25 u209 u
Period66
GroupN/A16
Blocksp
Phase at STPsolidsolid
Electron configuration[Xe]6s24f75d1[Xe]6s24f145d106p4
Oxidation states[0, 1, 2, 3][-2, 2, 4, 5, 6]
Electronegativity (Pauling)1.22
Electron affinity0.132 eV1.9 eV
Density7900 kg/m³9320 kg/m³
Melting point1312.85 °C253.85 °C
Boiling point3272.85 °C961.85 °C
Discovery year18861898