The lanthanides. Oxidation states and some other features

Abstract

The stabilities of oxidation states +2, +3 and +4 of the lanthanides in solution and in the solid state are discussed in terms of energy cycles. The irregular variation of the third and fourth ionization energies is of decisive importance in determining the relative stabilities of the various oxidation states. Some other features such as electronic configurations and the variation of properties with atomic number and L quantum number are also discussed. Important uses of the elements are mentioned.