Among the given species the Resonance stabilised carbocations are :

A s-block element (M) reacts with oxygen to form an oxide of the formula MO₂. The oxide is pale yellow in colour and paramagnetic. The element (M) is :

In the given reaction

3-Bromo-2, 2-dimethyl butane $$\buildrel {{C_2}{H_5}OH} \over \longrightarrow \mathop {'A'}\limits_{(Major\,\Pr oduct)} $$

Product A is :

The metal that can be purified economically by fractional distillation method is :