General properties of Lanthanides
The electronic configuration of Lanthanides is listed in the table. The fourteen electrons are filled in Ce to Lu with configuration [54Xe ]4f1-14 5d1 6s2
The common oxidation state exhibited by all the lanthanides is +3 (Ln3+) in aqueous solutions and in their solid compounds. Some elements exhibit +2 and +4 states as uncommon oxidation states.
La – +3
Ce – +3, +4, +2
Pr – +3, +4
Nd – +3, +4, +2
Radii of tripositive lanthanide ions
The size of M3+ ions decreases as we move through the lanthanides from lanthanum to lutetium. This steady decrease in ionic radii of M3+ cations in the lanthanide series is called Lanthanide contraction.