Argon vs Samarium

PropertyAr ArgonSm Samarium
Atomic number1862
SymbolArSm
NameArgonSamarium
Categorynoble-gaslanthanide
Standard Atomic Weight39.948 u150.36 u
Period36
Group18N/A
Blockps
Phase at STPgassolid
Electron configuration[Ne]3s23p6[Xe]6s24f6
Oxidation states[0][0, 1, 2, 3]
Electronegativity (Pauling)N/A1.17
Electron affinity-1 eV0.156 eV
Density1.7837 kg/m³7520 kg/m³
Melting point-189.35 °C1073.85 °C
Boiling point-185.85 °C1793.85 °C
Discovery year18941878