Neodymium vs Neptunium

PropertyNd NeodymiumNp Neptunium
Atomic number6093
SymbolNdNp
NameNeodymiumNeptunium
Categorylanthanideactinide
Standard Atomic Weight144.242 u237 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f4[Rn]7s25f46d1
Oxidation states[0, 2, 3, 4][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.141.36
Electron affinity1.913 eV0.48 eV
Density7010 kg/m³2.025000e+4 kg/m³
Melting point1020.85 °C643.85 °C
Boiling point3073.85 °C3901.85 °C
Discovery year18411940