Which of the following orbital diagrams correctly represents oxygen having six valence electrons?

• A. 1s: ↑↓ 2s: ↑↓ 2p: ↑↓ ↑↓ ↑↓
• B. 1s: ↑↓ 2s: ↑↓ 2p: ↑↓ ↑ ↑
• C. 1s: ↑↓ 2s: ↑↓ 2p: ↑↓ ↑↓ ↑
• D. 1s: ↑↓ 2s: ↑↓ 2p: ↑ ↑ ↑

Answer: (B)

Verified step by step guidance

1. Identify the total number of valence electrons for oxygen. Oxygen has 6 valence electrons, which are the electrons in the 2s and 2p orbitals.
2. Recall the order of filling orbitals: first fill the 2s orbital with 2 electrons (paired spins), then fill the 2p orbitals with the remaining 4 electrons.
3. Apply Hund's rule to the 2p orbitals: electrons fill degenerate orbitals singly with parallel spins before pairing up. This means place one electron in each of the three 2p orbitals before pairing any.
4. Distribute the 4 electrons in the 2p orbitals accordingly: place one electron in each of the three 2p orbitals, then add the fourth electron to pair up in one of the orbitals.
5. Verify the orbital diagram matches this distribution: 1s and 2s orbitals fully paired (↑↓), and 2p orbitals showing two electrons paired in one orbital (↑↓) and one electron each in the other two orbitals (↑ and ↑).