Praseodymium vs Thorium

PropertyPr PraseodymiumTh Thorium
Atomic number5990
SymbolPrTh
NamePraseodymiumThorium
Categorylanthanideactinide
Standard Atomic Weight140.90766 u232.0377 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f3[Rn]7s26d2
Oxidation states[0, 1, 2, 3, 4, 5][-1, 1, 2, 3, 4]
Electronegativity (Pauling)1.131.3
Electron affinity0.962 eV0.607 eV
Density6770 kg/m³1.172000e+4 kg/m³
Melting point930.85 °C1749.85 °C
Boiling point3519.85 °C4787.85 °C
Discovery year18851828