The electronic configuration of $Yb^{2+}$ is:

What is the general formula of lanthanoid hydroxide? (Consider $Ln$ as any lanthanoid element)

Which of the following elements are analogous to the lanthanides?

The electronic configurations of $Eu$ (Atomic No. $63$),$Gd$ (Atomic No. $64$) and $Tb$ (Atomic No. $65$) are

In the lanthanide series,the basicity of the lanthanide hydroxides:

Identify the correct statements about lanthanoids:
$I$. $Ce^{4+}$ and $Tb^{4+}$ act as oxidising agents.
$II$. $Eu^{2+}$ and $Yb^{2+}$ act as reducing agents.
$III$. Mischmetal is an alloy of $95 \%$ lanthanoid metal and $5 \%$ iron.
$IV$. $La^{3+}$ and $Ce^{4+}$ are diamagnetic in nature.