Question

Generally lanthanides element show +3 oxidation state but cerium shows +4 oxidation state.why ?

Answer 1

Dear student,
Most stable oxidation state of Lanthanides is +3. But some show +2 and +4 oxidation states due to presence of half-filled or fully-filled or empty f-sub shells.
Cerium's atomic number = 58
electronic configuration = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 4f¹ 5d¹ 6s²
So, it shows +4 oxidation state because after losing 1 electron from the f sub shell it attains noble gas configuration.
Regards
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