Hafnium vs Tantalum

Side-by-side comparison of Hafnium (Hf, element 72) and Tantalum (Ta, element 73) by atomic structure and physical properties.

PropertyHf Hafnium Ta Tantalum
Atomic number7273
SymbolHfTa
NameHafniumTantalum
Categorytransition-metaltransition-metal
Standard Atomic Weight178.49 u180.94788 u
Period66
Group45
Blockdd
Phase at STPSolidSolid
Electron configuration[Xe]4f145d26s2[Xe]4f145d36s2
Oxidation states[-2, 0, 1, 2, 3, 4][-3, -1, 0, 1, 2, 3, 4, 5]
Electronegativity (Pauling)1.31.5
Electron affinity0.178 eV0.328859 eV
Density1.33e+4 kg/m³1.64e+4 kg/m³
Melting point2232.85 °C3016.85 °C
Boiling point4602.85 °C5457.85 °C
Discovery year19221802

Key Differences

PropertyHf HafniumTa Tantalum
Standard Atomic Weight178.49 u ↓ lower180.94788 u ↑ higher
Density1.33e+4 kg/m³ ↓ lower1.64e+4 kg/m³ ↑ higher
Melting point2232.85 °C ↓ lower3016.85 °C ↑ higher
Boiling point4602.85 °C ↓ lower5457.85 °C ↑ higher
Electronegativity (Pauling)1.3 ↓ lower1.5 ↑ higher
Electron affinity0.178 eV ↓ lower0.328859 eV ↑ higher
Group4 5
Electron configuration[Xe]4f145d26s2 [Xe]4f145d36s2
Discovery year1922 1802