Gadolinium vs Neptunium

PropertyGd GadoliniumNp Neptunium
Atomic number6493
SymbolGdNp
NameGadoliniumNeptunium
Categorylanthanideactinide
Standard Atomic Weight157.25 u237 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f75d1[Rn]7s25f46d1
Oxidation states[0, 1, 2, 3][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.21.36
Electron affinity0.132 eV0.48 eV
Density7900 kg/m³2.025000e+4 kg/m³
Melting point1312.85 °C643.85 °C
Boiling point3272.85 °C3901.85 °C
Discovery year18861940