Polonium vs Americium

PropertyPo PoloniumAm Americium
Atomic number8495
SymbolPoAm
NamePoloniumAmericium
Categorymetalloidactinide
Standard Atomic Weight209 u243 u
Period67
Group16N/A
Blockps
Phase at STPsolidsolid
Electron configuration[Xe]6s24f145d106p4[Rn]7s25f7
Oxidation states[-2, 2, 4, 5, 6][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)21.3
Electron affinity1.9 eV0.1 eV
Density9320 kg/m³1.369000e+4 kg/m³
Melting point253.85 °C1175.85 °C
Boiling point961.85 °C2010.85 °C
Discovery year18981944