Question

If $n$ and $I$ are respectively the principal and azimuthal quantum numbers, then the expression for calculating the total number of electrons in any orbit is

• A. $\sum\limits_{l=1}^{l=n} 2\left(2l+1\right)$
• B. $\sum\limits_{l=1}^{l=n-1} 2\left(2l+1\right)$
• C. $\sum\limits_{l=0}^{l=n+1} 2\left(2l+1\right)$
• D. $\sum\limits_{l=0}^{l=n-1} 2\left(2l+1\right)$

Answer 1

Answer: (D)

Total number of electrons in an orbital $= 2 (2l + 1).$
The value of $l$ varies from $0$ to $n - 1.$
$\therefore $ Total numbers of electrons in any orbit= $\sum\limits_{l=0}^{l=n+1} 2\left(2l+1\right)$