Question

The maximum number of electrons that can be filled in the shell with the principal quantum number $n=3$ is

• A. $18$
• B. $9$
• C. $8$
• D. $2$

Answer 1

The correct option is A $18$

Maximum number of electrons that can be filled with the principal quantum number ${}^{\prime }{n}^{\prime }=2\times n^2.$

Here, $n=3$

$\therefore$ Maximum number of electrons that can be accommodated in this shell $=2\times 9=18$

Therefore, option A is correct.