Gadolinium vs Protactinium

PropertyGd GadoliniumPa Protactinium
Atomic number6491
SymbolGdPa
NameGadoliniumProtactinium
Categorylanthanideactinide
Standard Atomic Weight157.25 u231.03588 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f75d1[Rn]7s25f26d1
Oxidation states[0, 1, 2, 3][2, 3, 4, 5]
Electronegativity (Pauling)1.21.5
Electron affinity0.132 eV0.123 eV
Density7900 kg/m³1.537000e+4 kg/m³
Melting point1312.85 °C1571.85 °C
Boiling point3272.85 °C-273.15 °C
Discovery year18861913