Argon vs Curium

PropertyAr ArgonCm Curium
Atomic number1896
SymbolArCm
NameArgonCurium
Categorynoble-gasactinide
Standard Atomic Weight39.948 u247 u
Period37
Group18N/A
Blockps
Phase at STPgassolid
Electron configuration[Ne]3s23p6[Rn]7s25f76d1
Oxidation states[0][3, 4, 5, 6]
Electronegativity (Pauling)N/A1.3
Electron affinity-1 eV0.277 eV
Density1.7837 kg/m³1.351000e+4 kg/m³
Melting point-189.35 °C1344.85 °C
Boiling point-185.85 °C3126.85 °C
Discovery year18941944