Which property of an electron in an atom is determined by the principal quantum number (n)?

• A. The orientation of the orbital in space
• B. The spin direction of the electron
• C. The energy level and relative size of the orbital
• D. The shape of the orbital

Answer: (C)

Verified step by step guidance

1. Understand that the principal quantum number, denoted as \(n\), is one of four quantum numbers used to describe the properties of electrons in atoms.
2. Recall that \(n\) primarily determines the energy level of an electron within an atom, which corresponds to the electron's shell or main energy level.
3. Recognize that as \(n\) increases, the electron's orbital is generally larger and the electron is found farther from the nucleus, indicating the relative size of the orbital.
4. Note that other properties such as the shape of the orbital are determined by the azimuthal quantum number (\(l\)), the orientation by the magnetic quantum number (\(m_l\)), and the spin direction by the spin quantum number (\(m_s\)).
5. Therefore, the principal quantum number \(n\) specifically determines the energy level and relative size of the orbital.