Question

Maximum number of electron that may be present on 4f-orbital is:
A. 2
B. 4
C. 7
D. 14

Answer 1

Hint: To determine the maximum number of electrons present in the 4f orbital, first we need to find out the azimuthal quantum number. From the azimuthal quantum number, the permissible value of magnetic quantum number is obtained from which we can get the number of orbitals present in the 4f orbital. In each orbital of any subshell, two electrons can be occupied which will have opposite spin.

Complete step by step answer: The electron present in the atom can be described by four sets of quantum number, Principal quantum number which is denoted by n (Possible value are 1, 2, 3, 4,….), Azimuthal quantum number which is denoted by l (possible values are 0, 1, 2, 3,….,(n-1), magnetic quantum number which is denoted by ${m_l}$ (possible values-l,…….,-1,0,1,…..,+l and spin quantum number which is denoted by ${m_s}$(possible values +1/2, -1/2.
For a 4f orbital, the principal quantum number is n = 4, the azimuthal quantum number is 3. The values of magnetic quantum numbers will be -3, -2, -1, 0, +1, +2, +3.
Total 7 orbitals are present in 4f subshell. Each orbital can contain two electrons which are present in opposite directions. So a total 14 electrons are present in a 4f orbital.
So, the correct answer is “Option D”.

Note:
The azimuthal quantum number is also known as angular momentum quantum number or orbital quantum number. It describes the subshell and determines the magnitude of the azimuthal quantum number.