Which of the following best explains why fluorine has a high electronegativity?

• A. Fluorine has a large atomic radius, allowing it to easily share electrons with other atoms.
• B. Fluorine has a completely filled valence shell, making it highly reactive and electronegative.
• C. Fluorine has a small atomic radius and a high effective nuclear charge, which strongly attracts bonding electrons.
• D. Fluorine has a low effective nuclear charge, resulting in weak attraction for bonding electrons.

Answer: (C)

Verified step by step guidance

1. Understand the concept of electronegativity: it is the tendency of an atom to attract bonding electrons towards itself in a chemical bond.
2. Recall that electronegativity generally increases across a period in the periodic table due to increasing effective nuclear charge and decreasing atomic radius.
3. Analyze fluorine's position in the periodic table: it is in the second period and group 17, meaning it has a high effective nuclear charge and a small atomic radius.
4. Recognize that a small atomic radius means the nucleus is closer to the bonding electrons, and a high effective nuclear charge means the nucleus has a strong pull on those electrons.
5. Conclude that fluorine's high electronegativity is best explained by its small atomic radius combined with a high effective nuclear charge, which strongly attracts bonding electrons.