Praseodymium vs Samarium

PropertyPr PraseodymiumSm Samarium
Atomic number5962
SymbolPrSm
NamePraseodymiumSamarium
Categorylanthanidelanthanide
Standard Atomic Weight140.90766 u150.36 u
Period66
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f3[Xe]6s24f6
Oxidation states[0, 1, 2, 3, 4, 5][0, 1, 2, 3]
Electronegativity (Pauling)1.131.17
Electron affinity0.962 eV0.156 eV
Density6770 kg/m³7520 kg/m³
Melting point930.85 °C1073.85 °C
Boiling point3519.85 °C1793.85 °C
Discovery year18851878