Which of the following statements are correct about $Zn,\,Cd$ and $Hg$ ?
$(I)$ they exhibit high enthalpies of atomisation as the $d-$ subshell is full
$(II)$ $zn$ and $Cd$ do not show variable oxidation states while $Hg$ shows $+ I$ and $+ II$
$(III)$ Compound of $Zn,\,Cd$ and $Hg$, are paramagnetic in nature
$(IV)$ $Zn,\,Cd$ and $Hg$ are called soft metals
$I,\,II,\,III$
$I,\,III$
$II,\,IV$
$IV$ only
Hydrated $C{u^{ + 2}}$ ion will be
Paris green is
Electrons in a paramagnetic compound are
Why do the transition elements exhibit higher enthalpies of atomisation?
Which of the following pairs of elements cannot form an alloy