NEETChemistryStructure of Atom
The maximum numerical value of the magnetic quantum number ( m_l ) observed for an electron in an atom's ground state is +2 . What is the minimum possible value of the principal quantum number ( n ) for this electron, and what is the total number of orbitals present in that principal shell?
Options
- An = 3 , total orbitals = 9
- Bn = 2 , total orbitals = 4
- Cn = 3 , total orbitals = 5
- Dn = 3 , total orbitals = 18
Correct answer
A. n = 3 , total orbitals = 9
Step-by-step solution
The magnetic quantum number m_l can take integral values from -l to +l , including zero. If the maximum observed value of m_l is +2 , the azimuthal quantum number l must be at least 2 (which corresponds to a d-subshell). The principal quantum number n must be strictly greater than l ( n > l ). Therefore, the minimum possible value for n is 2 + 1 = 3 . For a principal shell with quantum number n , the total number of orbitals is given by the formula n^2 . For n = 3 , the total number of orbitals is 3^2 = 9 . Note: 5