Name the lanthanoid element which exhibits a +4 oxidation state besides the +3 oxidation state.
Answer: Cerium (Ce⁴⁺, attaining the stable 4f⁰ configuration).
Solution
Cerium (Z = 58) shows +4 besides +3: losing four electrons gives Ce with the extra-stable noble-gas (4f) configuration.
(Ce is a good oxidant, reverting to the common +3 state.)
(Ce is a good oxidant, reverting to the common +3 state.)
CBSE Class 12 Board · 2002 · Delhi Compartment · Subjective