Argon vs Polonium

PropertyAr ArgonPo Polonium
Atomic number1884
SymbolArPo
NameArgonPolonium
Categorynoble-gasmetalloid
Standard Atomic Weight39.948 u209 u
Period36
Group1816
Blockpp
Phase at STPgassolid
Electron configuration[Ne]3s23p6[Xe]6s24f145d106p4
Oxidation states[0][-2, 2, 4, 5, 6]
Electronegativity (Pauling)N/A2
Electron affinity-1 eV1.9 eV
Density1.7837 kg/m³9320 kg/m³
Melting point-189.35 °C253.85 °C
Boiling point-185.85 °C961.85 °C
Discovery year18941898