(a) Show the formation of NaCl from sodium and chlorine atoms by the transfer of electron(s).
(b) Why has sodium chloride a high melting point?
(c) Name the anode and the cathode used in the electrolytic refining of impure copper metal.

(a) Formation of sodium chloride by electron transfer:

Electronic arrangement of sodium and chlorine:


Formation of ionic bond:


(b) Sodium chloride has a high melting point because of strong lattice structure formed due to the ionic bond. Interatomic attractive forces hold the two elements tightly and increase their boiling point.

(c) In the electrolytic refining of impure copper metal, the impure copper plates act as the anode while a thin sheet of pure copper act as the cathode.