Question

Write scientific reason.

Elements belonging to the same group have the same valency.

Answer 1

1. The valency of an element is determined by the number of valence electrons in the outermost shell of an atom of an element.
2. All the elements in a group have the same number of valence electrons. Therefore, elements in the same group should have the same valency.
3. For example, the elements of group I contain only one valence electron, the valency of elements of group I is one. Similarly for group II, the valency is two.