Cerium (Z = 58) is an important member of the lanthanoid series. Which of the following correctly describes the magnetic nature and the chemical behaviour of the Ce ⁴⁺ ion in aqueous solution?

Step-by-step solution

The electronic configuration of the Cerium atom (Z = 58) is [ Xe ] 4 f ^1 5 d ^1 6 s ^2 . The Ce ⁴⁺ ion is formed by the loss of all four valence electrons, resulting in the noble gas core configuration of [ Xe ] . Since it has zero unpaired electrons, the Ce ⁴⁺ ion is diamagnetic. The most stable oxidation state for lanthanoids is +3. Therefore, Ce ⁴⁺ has a strong tendency to gain one electron and revert to the more stable +3 state ( Ce ³⁺ ). Because it readily undergoes reduction, Ce ⁴⁺ acts as a strong oxidising