What is the total number of orbitals associated with the principal quantum number 3?
3
6
9
12
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC Geoscientist – 2023
For n = 3, the possible values of l are 0, 1, and 2.
l = 0 corresponds to the s subshell. The number of orbitals in an s subshell is 1 (m_l = 0).
l = 1 corresponds to the p subshell. The number of orbitals in a p subshell is 3 (m_l = -1, 0, +1).
l = 2 corresponds to the d subshell. The number of orbitals in a d subshell is 5 (m_l = -2, -1, 0, +1, +2).
The total number of orbitals associated with a principal quantum number n is the sum of the number of orbitals in each subshell:
Total orbitals for n=3 = (number of orbitals for l=0) + (number of orbitals for l=1) + (number of orbitals for l=2)
Total orbitals for n=3 = 1 (3s) + 3 (3p) + 5 (3d) = 9.
Alternatively, the total number of orbitals in a shell with principal quantum number n is given by n².
For n = 3, total orbitals = 3² = 9.