Chemistry - f-block Question with Solution | TestHub

The statement A is correct. Ce⁴⁺ has the electron configuration $[Xe]$, which is a noble gas configuration.

B is incorrect: Yb²⁺ is $[Xe]4f^{14}$ (fully filled), and Eu²⁺ is $[Xe]4f^7$ (half-filled).

C is incorrect: Th⁴⁺ is $[Rn]$, so it has no 5f electrons.