(a) Sodium.
(b) (i) Calamine; Zinc carbonate, ZnCO3
(ii) Zinc blende; Zinc sulphide, ZnS
(c) Mercury (II) sulphide ore is roasted in air when mercury (II) oxide is formed.

When this mercury (II) oxide is heated to about 300oC, it decomposes to form mercury metal.

(d) Anode - Thick block of impure metal M
Cathode - Thin strip of pure metal M
Electrolyte - Water soluble salt (of metal M).
(e) (i) Copper
(ii) Zinc
(iii) Nickel
(iv) Gold
(v) Silver