Question

Answer quickly !!!!!!!!!!!!!!!!!!!!!

Answer 1

Valency is the combining capacity of an element.

When we move down a group, the number of shells increases while the number of valence electrons remains same, so the valency down a group remains same for a group.

GROUP 1

In this group, all the elements have a valency of 1.

GROUP 2

In this group, all the elements have a valency = 2

GROUP 18

All elements in this group have already filled valence shells, hence rendering the valency zero