It is harder to remove an electron from fluorine than from carbon because fluorine's outermost electrons are held more tightly by its nucleus. This is due to fluorine's higher effective nuclear charge and smaller atomic radius compared to carbon, causing a stronger electrostatic attraction between the nucleus and the outer electrons.
Factors Making Fluorine's Electrons More Tightly Held
- Fluorine has 9 protons in its nucleus, compared to carbon's 6 protons. This means a stronger positive charge pulls on the electrons.
- The outermost electrons in fluorine experience less shielding from inner electrons because fluorine has fewer electron shells than carbon, meaning the outer electrons feel a greater net nuclear charge.
- Fluorine's small atomic radius brings its valence electrons closer to the nucleus, increasing the electrostatic attraction.
- Overall, the effective nuclear charge (nuclear charge minus electron shielding) is higher for fluorine, so more energy is needed to remove an electron from fluorine compared to carbon.
Thus, fluorine's outermost electrons are more tightly held and require more energy to remove because of its greater nuclear charge, smaller size, and less shielding effects compared to carbon.