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

Explanation

Atomic number of Na = 11
`therefore` Its electronic configuration is 2, 8, 1
Number of electrons in `Na^(+)` = 11 - 1 = 10
`therefore` Electronic configuration of `Na^(+)` = 2, 8
i.e. `Na^(+)` has 2 electrons in K shell and 8 electrons in L shell. According to Bohr and Bury, K shell can accommodate maximum of 2 and L shell can accommodate maximum of 8 electrons. Thus `Na^(+)` has completely filled K and L-shells.