Beryllium vs Polonium

PropertyBe BerylliumPo Polonium
Atomic number484
SymbolBePo
NameBerylliumPolonium
Categoryalkaline-earth-metalmetalloid
Standard Atomic Weight9.012183 u209 u
Period26
Group216
Blocksp
Phase at STPsolidsolid
Electron configuration[He]2s2[Xe]6s24f145d106p4
Oxidation states[0, 1, 2][-2, 2, 4, 5, 6]
Electronegativity (Pauling)1.572
Electron affinity-0.52 eV1.9 eV
Density1850 kg/m³9320 kg/m³
Melting point1286.85 °C253.85 °C
Boiling point2470.85 °C961.85 °C
Discovery year17971898