Question

Define valency shell​

Answer 1

$\huge\mathfrak\red{Answer}$

Valence Shell is the outermost shell of an atom containing the valence electrons.

Answer 2

Hii...

=> In chemistry and physics, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.