Answer the following question:
 
\(Na^+\) has completely filled K and L shells. Explain.
 
Atomic number of \(Na\) \(=\) \(11\)
Number of protons \(=\) 
Number of electrons \(=\)
Electronic configuration of \(Na\) \(=\)
\(Na\) to become stable and forms \(Na^+\) ion. Hence, it has completely filled K and L shells, attaining the stable configuration  .