Question

Assertion:- An element X has a mass number 4 and atomic number 2, have zero
valency.
Reason:- Valency is the combining capacity of the atom of an element with the
atoms of other element(s) in order to complete its octet.​

Answer 1

Option (A) Both A and R are correct and R is the correct explanation of A.

Since every element tries to gain or donate electrons in order to complete its octet and gain a stable and a noble gas configuration. This property is called valency

Hope you Understand