Terbium vs Hafnium

PropertyTb TerbiumHf Hafnium
Atomic number6572
SymbolTbHf
NameTerbiumHafnium
Categorylanthanidetransition-metal
Standard Atomic Weight158.92535 u178.49 u
Period66
GroupN/A4
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f9[Xe]6s24f145d2
Oxidation states[0, 1, 2, 3, 4][-2, 0, 1, 2, 3, 4]
Electronegativity (Pauling)N/A1.3
Electron affinity1.124 eV0.178 eV
Density8230 kg/m³1.330000e+4 kg/m³
Melting point1355.85 °C2232.85 °C
Boiling point3229.85 °C4602.85 °C
Discovery year18431911