Question

In which shell the last elctron will stay for sodium atom ( ${}_{12}^{25}Na$ ) .

• A. K
• B. L
• C. M
• D. N

Answer 1

The correct option is C M

Atomic number (Z) of sodium atom = 11
Atomic number = Total number of electros = 11
In maximum, number of elctrons in K = 2 and that for L is 8. So, the remaining last electron of the sodium stays at M shell