The outer electron configuration of $Gd$ (Atomic No.: $64$) is:

Which of the following statements are correct about $Zn, Cd$ and $Hg$?
$A$. They exhibit high enthalpy of atomization as the d-subshell is full.
$B$. $Zn$ and $Cd$ do not show variable oxidation state while $Hg$ shows $+I$ and $+II$.
$C$. Compounds of $Zn, Cd$ and $Hg$ are paramagnetic in nature.
$D$. $Zn, Cd$ and $Hg$ are called soft metals.
Choose the most appropriate from the options given below:

What are the different possible oxidation states exhibited by scandium $(Sc)$?

Identify the components of the alloy known as German Silver.

Which of the following elements does not belong to the first transition series?

Although $Zr$ belongs to the $4d$ transition series and $Hf$ belongs to the $5d$ transition series,it is quite difficult to separate them. Why?