Which of the comparison regarding $Zn,\,Cd,\,Hg$ is/are incorrect ?
$(I)$ $ZnCl_2$ is ionic whereas $CdCl_2$ and $HgCl_2$ are covalent
$(II)$ $Zn$ and $Cd$ dissolves in dilute acid $(HCl)$ liberating $H_2$ but $Hg$ can not
$(III)$ $Zn$ and $Cd$ forming with ppt. of $Zn(OH)_2$ and $Cd(OH)_2$ but $Hg$ forms coloured ppt. of
$(IV)$ all from $A_2^{2+}$ type ion
only $III$
$I, III, IV$
$I$ and $III$
all of these
The ability to form complex compounds by the transitional metal ion is due to
Choose the correct statement regarding transition elements?
Identify incorrect statement
Consider the following reaction
$\mathrm{MnO}_2+\mathrm{KOH}+\mathrm{O}_2 \rightarrow \mathrm{A}+\mathrm{H}_2 \mathrm{O} .$
Product ' $A$ ' in neutral or acidic medium disproportionate to give products ' $\mathrm{B}$ ' and ' $\mathrm{C}$ ' along with water. The sum of spin-only magnetic moment values of $B$ and $C$ is . . . . . .$BM$. (nearest integer)
(Given atomic number of $\mathrm{Mn}$ is $25$ )
Besides $Zn$ and $Cu$, german silver contains the metal