Explain Comparison of Lanthanides and Actinides

Lanthanides and Actinides both show close resemblance because these involve filling of f-subshells. Both have colored ions, low electronegativity, high re-activity and show magnetic properties. However, these also differ from each other as shown in the following explanation.


  • Binding energies of 4f electrons are higher.
  • Maximum oxidation satate exhibited by lanthanides is +4 e.g. Ce4+
  • 4f electrons have greater shielding effect.
  • Most of their ions are colourless.
  • They are paramagnetic but magnetic properties can be easily explained.
  • They do not form complexes easily.
  • Except promethium, they are non-radioactive.
  • Their compounds are less basic.
  • They do not form oxocations.


  • Binding energies of 5f electrons are lower.
  • Due to lower binding energies they show higher oxidation states such as +4, +5 and +6. Uranium exhibits +6 oxidation state in UF6 and UO2Cl2
  • 5f electrons have poor shielding effect.
  • Most of their ions are coloured U3+ (red), U4+ (green) and UO22+ (yellow)
  • They are also paramagnetic but their magnetic properties are very difficult to interpret.
  • They have much greater tendency to form complexes.
  • All of them are radioactive.
  • Their compounds are more basic.
  • They form oxocations such as UO22+, UO+, NpO2+, PuO2+.