Question

Reactivity of group IA and group IIA elements increases as we go from top to bottom in the group but the reactivity decreases in case of group VIIA as we go down in the group. Justify the statement.

Answer 1

The IA and IIA group elements are called S block elements(alkali and alkaline earth ), where as VIIA group elements are halogens. To explain this we should consider the valence electrons, which play an important role in their reactivity.
The S block elements are more electropositive elements, the electropostiveness( tendency to lose valence electrons) increases as we go from top to bottom. This is due to the increased size of the atom, which makes the valence electron less shielded (control over nucleus) as result are able to donate electrons very easily and form ions. This means reactivity increases as we go from top to bottom.
In contrast, if you consider the P block elements, the electronegativity (tendency to gain electrons) increases as we go from top to bottom. As the size of atom increases from top to bottom, the tendency to attract the electron decreases due to bigger

Answer 2

thank u soooo mch sir!

Answer 3

ur welcome