What is the only possible value of the magnetic quantum number (m_l) for an electron in an s orbital?

• A. +1
• B. 0
• C. +2
• D. -1

Answer: (B)

Verified step by step guidance

1. Understand that the magnetic quantum number (m_l) describes the orientation of an orbital in space and can take on integer values between -l and +l, where l is the azimuthal quantum number.
2. Recognize that for an s orbital, the azimuthal quantum number (l) is 0.
3. Apply the rule for the magnetic quantum number: m_l can range from -l to +l. Since l = 0 for an s orbital, m_l can only be 0.
4. Conclude that the only possible value for m_l in an s orbital is 0, as there are no other integers between -0 and +0.
5. This means that the s orbital is spherically symmetric and does not have any orientation in space, which is consistent with m_l = 0.