Thulium vs Neptunium

PropertyTm ThuliumNp Neptunium
Atomic number6993
SymbolTmNp
NameThuliumNeptunium
Categorylanthanideactinide
Standard Atomic Weight168.93422 u237 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f13[Rn]7s25f46d1
Oxidation states[0, 1, 2, 3][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.251.36
Electron affinity1.029 eV0.48 eV
Density9320 kg/m³2.025000e+4 kg/m³
Melting point1544.85 °C643.85 °C
Boiling point1949.85 °C3901.85 °C
Discovery year18791940