The two metals which can be extracted just by heating their sulphides in the air are:
(a) sodium and copper (b) copper and aluminium
(c) potassium and zinc (d) mercury and copper
Answer :
(d) mercury and copper
Both mercury and copper are less reactive metals and are placed low in the reactivity series. Hence, they can be extracted by heating their sulphides in the air and further reducing their oxides by heating.