Identify the element for which the electronic configuration in the $+3$ oxidation state is $[Ar] 3d^5$:

Which one of the following ions has the same number of unpaired electrons as those present in $V^{3+}$ ion?

Which of the following is responsible for the stability of $Ce^{4+}$?

The correct order of ionic radii for $Y^{3+}$,$La^{3+}$,$Eu^{3+}$,and $Lu^{3+}$ is:

Effective magnetic moment of $Sc^{3+}$ ion is

Gadolinium (atomic number $= 64$) is a member of the $4f$ series. Its electronic configuration in the $+3$ oxidation state is $[Xe] 4f^7$. What is the ground state electronic configuration of gadolinium?