Answer:
F
General Formulas and Concepts:
- Ionization Energy (I.E): Amount of energy (joules) needed to remove an electron from the atom
- Periodic Trends
Step-by-step explanation:
The trend for 1st I.E increases to the right and up. Therefore, the top right corner of the Periodic Table would have the highest 1st I.E.
Oxygen and Fluorine are in Period 2 while Sulfur and Chlorine are in Period 3. We then know that Oxygen and Fluorine will have higher I.E's than Sulfur and Chlorine.
Oxygen is in Group 16 while Fluorine is in Group 17. Since Fluorine is farther to the right of the Periodic Table, it will have the highest I.E out of all 4 elements.
The reason why F has a larger I.E than O is because F has a larger Zeff. Since Fluorine has more protons in the nucleus than O, the FOA between the nucleus and the e⁻ are greater than those of O. Therefore, it takes more energy to remove an e⁻ from F than O.
The reason why F has a larger I.E than S and Cl is because S and Cl have more shielding effect than F. Since S and Cl has more core e⁻, it weakens the FOA between the nucleus and the outermost shell e⁻, thus making it easier to remove. F has less core e⁻ and therefore there is less of a shielding effect and thus the FOA is larger and requires more energy to remove.