The statement(s) that are correct about the species $$\mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Na}^{+}$$ and $$\mathrm{Mg}^{2+}$$.

(A) All are isoelectronic

(B) All have the same nuclear charge

(C) $$\mathrm{O}^{2-}$$ has the largest ionic radii

(D) $$\mathrm{Mg}^{2+}$$ has the smallest ionic radii

Choose the most appropriate answer from the options given below :

The reaction at cathode in the cells commonly used in clocks involves.

The following reaction occurs in the Blast furnance where iron ore is reduced to iron metal

$$\mathrm{Fe}_2 \mathrm{O}_{3(s)}+3 \mathrm{CO}_{(g)} \rightleftharpoons \mathrm{Fe}_{(j)}+3 \mathrm{CO}_{2(g)}$$

Using the Le-chatelier's principle, predict which one of the following will not disturb the equilibrium.

Identify compound (Z) in the following reaction sequence.