Question

give reason element present some group have same valency​

Answer 1

Answer:

Elements of the same group have same or almost same valency or oxidation state.

Explanation:

This is because, modern periodic law of element may be defined as the physical and chemical properties of the elements are periodic functions of their atomic numbers, hence the elements of same group will result to have the same number of valence electrons in their valence shell. We, know that the number of valence electrons is equal to the valency of anmy element in most case, thus the elements of same group have same valency.

Answer 2

Elements in same group show same valency because they have same number of electrons in ther outermost shell i.e. Valence shell.Since valency depends upon the valence electrons so they have same valency. Elements in the same group have same valancy. This is because the elements have same number of valance electrons.