Promethium vs Lead

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PropertyPm PromethiumPb Lead
Atomic number6182
SymbolPmPb
NamePromethiumLead
Categorylanthanidepost-transition-metal
Standard Atomic Weight145 u207.2 u
Period66
GroupN/A14
Blocksp
Phase at STPsolidsolid
Electron configuration[Xe]6s24f5[Xe]6s24f145d106p2
Oxidation states[2, 3][-4, -2, -1, 0, 1, 2, 3, 4]
Electronegativity (Pauling)N/A2.33
Electron affinity0.129 eV0.364 eV
Density7260 kg/m³1.134200e+4 kg/m³
Melting point1041.85 °C327.46 °C
Boiling point2999.85 °C1748.85 °C
Discovery year19022021