The characteristic oxidation state of Lanthanoids is +3 but Ce shows +4 oxidation state becau.............
(A) it has variable ionization enthalpy
(B) it has a tendency to attain noble gas configuration
(C) it has a tendency to attain $f^0$ configuration
(D) it resembles $Pb^{4+}$
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (B) and (C) only
Lanthanoids generally show +3 oxidation state.
Cerium (Ce) shows +4 oxidation state because:
- Ce⁴⁺ has an f⁰ configuration, which is particularly stable
- It also corresponds to attaining a noble gas–like configuration (similar to Xe core)
Evaluate statements:
- (A) Variable ionization enthalpy → not the main reason INCORRECT
- (B) Tendency to attain noble gas configuration → CORRECT
- (C) Tendency to attain f⁰ configuration → CORRECT
- (D) Resembles Pb⁴⁺ → irrelevant INCORRECT