The most basic oxide of lanthanoids is $:-$

Identify the correct statements from the following :
$I$. The ionic radius of $Pr^{3+}, Dy^{3+}$ and $Sm^{3+}$ follow the order,$Sm^{3+} > Pr^{3+} > Dy^{3+}$.
$II$. $Eu^{2+}$ acts as a strong reducing agent.
$III$. $Pu$ exhibits $+7$ oxidation state.

What is the correct electronic configuration of $Th$ $(Z=90)$?

The correct increasing order of basic character of $Ce(OH)_3$,$Gd(OH)_3$ and $Nd(OH)_3$ is

The number of $f$ electrons in the ground state electronic configuration of $Np$ $(Z=93)$ is ....... .

Which among the following properties of lanthanoids is $NOT$ true?