Which of the following statements is correct with respect to the electron spin quantum number?

• A. The spin quantum number determines the size of the orbital.
• B. The spin quantum number is always zero for electrons.
• C. The spin quantum number describes the orientation of the orbital in space.
• D. The spin quantum number can have values of +1/2 or -1/2.

Answer: (D)

Verified step by step guidance

1. Recall that the electron spin quantum number, denoted as \(m_s\), describes the intrinsic angular momentum (spin) of an electron, which is a fundamental property independent of the electron's position or orbital shape.
2. Understand that \(m_s\) can only have two possible values: \(+\frac{1}{2}\) or \(-\frac{1}{2}\), representing the two possible spin orientations (commonly called 'spin up' and 'spin down').
3. Recognize that the spin quantum number does not determine the size of the orbital; that property is related to the principal quantum number \(n\).
4. Know that the spin quantum number is never zero for electrons; it must be either \(+\frac{1}{2}\) or \(-\frac{1}{2}\).
5. Note that the orientation of the orbital in space is described by the magnetic quantum number \(m_l\), not the spin quantum number.