`Na^(+)` has completely filled K and L shells. Explain.

Explanation

Atomic number of sodium (Na) = 11
No. of electrons in Na = 11
No. of electrons in Na. = 11 - 1 = 10
Electronic configuration of `Na^(+) to underset(K ) (2,) underset(L )(8)`
Thus, in `Na^(+)`, K and L shells are completely filled.