Assertion (A) : Outer most electronic configuration of most electropositive elements is $n{s}^{2}n{p}^3$

Reason (R): $n{s}^{2}n{p}^3$ is stable due to half filled subshell.

Assertion : It is incorrect ,  the correct fact is that  Outermost electronic configuration of most electropositive elements is   $n{p}^{6}n{s}^1$.

Reason:  R is correct- $n{s}^{2}n{p}^3$  is stable due to half filled subshell