Question

The maximum number of electrons in a shell can be calculated by the formula _______.

• A. ${\text{n}}^{\text{2}}$
• B. $\text{n}$
• C. $\text{2n}$
• D. ${\text{2n}}^{\text{2}}$

Answer 1

The correct option is D ${\text{2n}}^{\text{2}}$

The maximum number of electrons present in a shell is given by the formula $2{\text{n}}^2$, where ‘n’ is always natural number.
n represents the principal quantum number. It represents the size and the energy of the shell.
Hence, the maximum number of electrons in different shells are as follows:

1. First orbit or K-shell (n=1) =
2x$1^2$ = 2
2. Second orbit or L-shell (n=2) =
2x$2^2$ = 8
and so on.