Thulium vs Hafnium

PropertyTm ThuliumHf Hafnium
Atomic number6972
SymbolTmHf
NameThuliumHafnium
Categorylanthanidetransition-metal
Standard Atomic Weight168.93422 u178.49 u
Period66
GroupN/A4
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f13[Xe]6s24f145d2
Oxidation states[0, 1, 2, 3][-2, 0, 1, 2, 3, 4]
Electronegativity (Pauling)1.251.3
Electron affinity1.029 eV0.178 eV
Density9320 kg/m³1.330000e+4 kg/m³
Melting point1544.85 °C2232.85 °C
Boiling point1949.85 °C4602.85 °C
Discovery year18791911