If n and `l` are respectively the principal and azimuthal quantum numbers , then the expression for calculating the total number of electrons in any energy level is :

Options

A. `sum_(l = 1)^(l = n) 2(2 l + 1)`
B. `sum_(l = 1)^(l = n = 1) 2(2 l + 1)`
C. `sum_(l = 0)^(l = n + 1) 2(2 l + 1)`
D. `sum_(l = 0)^(l = n - 1) 2(2 l + 1)`

Answer

D

Explanation

(d) Total number of electrons in an orbital `= 2(2 l + 1)`
The value of `l` varies from `0` to `n - 1`.
`:.` Total number of electrons in any orbit `= sum_(l = 0)^(l = n + 1) 2 (2l + 1)`.