Mercury is purified by:

In the electrolytic refining of copper,$Ag$ and $Au$ are found

Copper is purified by electrolytic refining of blister copper. The correct statement$(s)$ about this process is(are):
$(A)$ Impure $Cu$ strip is used as cathode
$(B)$ Acidified aqueous $CuSO_4$ is used as electrolyte
$(C)$ Pure $Cu$ deposits at cathode
$(D)$ Impurities settle as anode-mud

High purity copper metal is obtained by

In van Arkel method,if $I_2$ is introduced at $1700 \ K$ over impure metal,the product will be :

The method used for the purification of $Indium$ is ..... .