`Ce^(4+)` is stable .This is because of

Options

A. half-filled d-orbital
B. all paired electrons in d-orbital
C. empty orbital
D. fully filled d-orbital

Answer

C

Explanation

The electronic configuration of Ce is
`Ce_(58)=[Xe]4f^(1)5d^(1)6s^(2)` (predicted) or
`=[Xe]4f^(2)5d^(0)6s^(2)` (observed)
`Ce^(4+)=[Xe]4f^(0)5d^(0)6s^(0)`
Since, in `+4` oxidation state, all 4f,5d and 6s orbitals are empty and Ce gains the stable configuration of nearest inert gas . Hence, `Ce^(4+)` is most stable .