06. GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS (HM)
Explanation:
Of the given metals, \(Cu , Mg , Cr\) and \(Ni ; Cu , Cr ,\) and \(Ni\) are \(d\)-block elements. As we know that reducing potential of \(s\)-block element is less than that of Hydrogen. So, on electrolysis of \(s\)-block elements, Hydrogen is released at Cathode, rather than Metal is deposited.