Four metals and their methods of refinement are giveni. Ni, Cu, Zr, Gaii. Electrolysis, Van Arkel process, zone refining, Mond's process Choose the right method for each:

Ni: Mond's process; Cu: Electrolysis; Zr: Van Arkel process; Ga: Zone refining.Van Arkel's method is a process of purification of metals involving, converting the metal to a volatile stable compound. The Van Arkel method is based on the principle of thermal decomposition of metal components, into respective metals.