Which of the following represents the correct electron configuration for a neutral atom of vanadium (atomic number 23)?

• A. 1s^2 2s^2 2p^6 3s^2 3p^6 3d^2 4s^3
• B. 1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1
• C. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 3d^4
• D. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^3

Answer: (D)

Verified step by step guidance

1. Identify the atomic number of vanadium, which is 23. This means a neutral vanadium atom has 23 electrons to place in orbitals.
2. Recall the order of filling orbitals according to the Aufbau principle: \$1s \rightarrow 2s \rightarrow 2p \rightarrow 3s \rightarrow 3p \rightarrow 4s \rightarrow 3d$.
3. Fill the orbitals in order with electrons, remembering that the \$4s\( orbital fills before the \)3d\( orbital. So, after filling \)1s^2 2s^2 2p^6 3s^2 3p^6\(, place electrons in \)4s\( before \)3d$.
4. Distribute the remaining electrons (after filling up to \$3p^6\() into \)4s\( and \)3d\( orbitals. Since \)4s\( fills first, place 2 electrons in \)4s\( and the remaining 3 electrons in \)3d$ to total 23 electrons.
5. Verify that the electron configuration matches the total number of electrons (23) and follows the correct filling order and Hund's rule, resulting in \$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^3$.