Answer to Question #61745 in Inorganic Chemistry for bharat

Question

The +3 oxidation state of lanthanum (Z = 57), gadolinium (Z = 64), and lutecium (Z = 71) is especially stable, why?

Answer 1

All of them, La, Gd, and Lu, are considered to belong to the lanthanide series, that has variable electron configuration 4f(0-14)5s25p65d16s2 . These elements may easily give up three valence electrons from the 5d and 6s subshells to form a stable +3 oxidation state. Within the lanthanides, the state is especially stable for La, Gd, Lu as they contain stable empty (La - 4f0), half filled (Gd - 4f7), and full filled (Lu - 4f14) f-subshell.