What is the ground-state electron configuration of the fluoride ion, F⁻?

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

Answer: (D)

Verified step by step guidance

1. Identify the atomic number of fluorine (F), which is 9. This means a neutral fluorine atom has 9 electrons.
2. Understand that the fluoride ion (F⁻) has gained one extra electron compared to the neutral atom, so it has 10 electrons in total.
3. Recall the order of filling electron orbitals according to the Aufbau principle: 1s, 2s, then 2p orbitals.
4. Write the electron configuration for 10 electrons: fill the 1s orbital with 2 electrons, the 2s orbital with 2 electrons, and the 2p orbitals with 6 electrons.
5. Express the ground-state electron configuration of the fluoride ion as \$1s^{2} 2s^{2} 2p^{6}$, indicating a full 2p subshell.