Question

Which of the following quantum numbers can't have zero value?

• A. Principal quantum number
• B. Azimuthal quantum number
• C. Magnetic quantum number
• D. Both (1) and (2)

Answer 1

The Correct Option is A

The correct answer is Principal quantum number.

Explanation:

Principal quantum number (n): This quantum number defines the main energy level or shell of an electron in an atom. It can never be zero. It starts from 1 (n = 1) and increases (n = 2, 3, etc.).

Azimuthal quantum number (l): This quantum number defines the shape of the orbital (subshells). The value of lll can be zero, for s-orbitals (which have spherical shapes). For p-orbitals, l=1l = 1l=1, d-orbitals have l=2l = 2l=2, and f-orbitals have l=3l = 3l=3.

Magnetic quantum number (m): This quantum number defines the orientation of the orbital in space. The value of mmm depends on lll and can range from −l-l−l to +l+l+l, including zero.

Thus, the principal quantum number (n) cannot have a value of zero, making it the correct answer.