Give reasons for the following:

(i) The size of a Cl^- ion is greater than the size of a Cl atom.

(ii) Argon atom is bigger than chlorine atom.

(iii) Chlorine is less reactive than fluorine.

(iv) Inert gases do not form ion.

(i) Cl^- has one more electron then Cl atom. Anion is formed by the gain of electron(s). Thus, the number of electron(s) are more than proton(s). The effective positive charge in the nucleus is less, so less inward pull is experienced. Hence, the size increases.

(ii) Argon is an inert gas and its outermost shell is complete. They have maximum number of electrons in their outermost orbit. Thus, the electronic repulsions are maximum. The effect of nuclear pull over the valence electrons is not seen. Hence, the size of the argon is greater then chlorine.

(iii) The chemical reactivity of non-metals decreases on going down the group as it depends upon the tendency to gain electrons, which decreases down the group. As fluorine is present at the top of the group it is more reactive than chlorine.

(iv) Inert gases do not form ion due to their stable electronic configuration, inert gases find it difficult to accept or lose electrons hence they do not form ion.