Argon vs Americium

PropertyAr ArgonAm Americium
Atomic number1895
SymbolArAm
NameArgonAmericium
Categorynoble-gasactinide
Standard Atomic Weight39.948 u243 u
Period37
Group18N/A
Blockps
Phase at STPgassolid
Electron configuration[Ne]3s23p6[Rn]7s25f7
Oxidation states[0][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)N/A1.3
Electron affinity-1 eV0.1 eV
Density1.7837 kg/m³1.369000e+4 kg/m³
Melting point-189.35 °C1175.85 °C
Boiling point-185.85 °C2010.85 °C
Discovery year18941944