The answer is II. Oxygen, IV. Sulfur, and V. Selenium.
Explanation:
Going down the list that was provided, we can use the periodic table of elements to determine the valence electrons.
- Nitrogen has 5 valence electrons
- Oxygen has 6 valence electrons
- Fluorine has 7 valence electrons
- Sulfur has 6 valence electrons
- Selenium has 6 valence electrons
Since oxygen, sulfur, and selenium all have 6 valence electrons, then that is the correct answer.
