The number of unpaired electrons in $M{n^{ + 3}}$ is
$4$
$3$
$2$
$0$
$F{e^{2 + }}$ shows
The element the usually does $NOT$ show variable oxidation states is
Which of the following will give green hydrated ion
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
Which of the following transition metal is used as a catalyst