Praseodymium vs Protactinium

PropertyPr PraseodymiumPa Protactinium
Atomic number5991
SymbolPrPa
NamePraseodymiumProtactinium
Categorylanthanideactinide
Standard Atomic Weight140.90766 u231.03588 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f3[Rn]7s25f26d1
Oxidation states[0, 1, 2, 3, 4, 5][2, 3, 4, 5]
Electronegativity (Pauling)1.131.5
Electron affinity0.962 eV0.123 eV
Density6770 kg/m³1.537000e+4 kg/m³
Melting point930.85 °C1571.85 °C
Boiling point3519.85 °C-273.15 °C
Discovery year18851913