Which of the following is not a valid set of quantum numbers
a. n = 2, l = 1 , m = 0
b. n = 1, l = 0, m = 0
c. n = 3, l = 3, m = 3

 C. n = 3, l = 3, m = 3

Explanation:

1. Principle Quantum Numbers: This quantum number describes the size of the orbital. It is represented by n. n = 1,2,3,4....

2. Azimuthal Quantum Number: This quantum number describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1). For l = 0,1,2,3... the orbitals are s, p, d, f...

3. Magnetic Quantum Number: This quantum number describes the orientation of the orbitals. It is represented as . The value of this quantum number ranges from . When l = 2, the value of will be -2, -1, 0, +1, +2.

A.  n = 2, l = 1 , m = 0 is possible.

B. n = 1, l = 0, m = 0   is possible.

C. n = 3, l = 3, m = 3 is not possible as for n = 3, l = 0, 1 and 2 and m = 0,+1, +2, -1 and -2.