How is the method of extraction of metals high up in the reactivity series different from that for metals in the middle ? Why can the same process not be applied for them ? Name the process used for extraction of these metals.

Explanation

Extraction of metals in the reactivity series of -

Metals high up in the reactivity series generally occur in the form of oxides which are quite stable. They cannot be obtained from their compounds by heating with carbon. For example, carbon cannot reduce the oxides of sodium, magnesium, calcium, aluminium, etc. to the respective metals. This is because these metals have high affinity for oxygen than carbon. For exatple, sodium, magnesium, calcium are obtained by the electrolysis of their molten chłorides. The process is called electrolytic reduction.
Metals in the middle occur in the form of carbonates and sulphides which are first converted into oxides by various methods and then into metals.
Same process cannot be applied for them due to difference in their reactivity. The process used for their extraction is calcination or roasting followed by reduction.