Electrons will first enterinto the orbital with the set of quantum numbers

Options

A. `n =5, l = 0`
B. `n = 4, l = 1`
C. `n = 3, l =2`
D. any of these

Answer

C

Explanation

According to the `(n +l)` rule, the lowest the value of `(n+l)` for an orbital the lower is its enegry. Here, all the orbitals have equal values of `(n +l)`.
If two or more orbitals have the same value of `(n+l)`, the orbital with lowest value of `n` has lower enegry. Thus, orbital `(n = 3,l = 2)` is having the lower enegry.