Why does electronegativity generally increase as you move from left to right across a period in the periodic table?

• A. Because the number of protons decreases, increasing the attraction for electrons.
• B. Because atoms gain more valence electrons, making them less likely to attract additional electrons.
• C. Because atomic radius decreases, causing the nucleus to attract bonding electrons more strongly.
• D. Because the number of energy levels increases, making electrons easier to attract.

Answer: (C)

Verified step by step guidance

1. Understand that electronegativity is the tendency of an atom to attract electrons in a chemical bond.
2. Recognize that as you move from left to right across a period, the number of protons in the nucleus increases, which increases the positive charge of the nucleus.
3. Note that the number of energy levels (electron shells) remains the same across a period, so the added protons pull the electrons closer without additional shielding from new shells.
4. Because the electrons are pulled closer, the atomic radius decreases, meaning the nucleus has a stronger effective nuclear charge on the valence electrons.
5. This stronger attraction causes atoms to more strongly attract bonding electrons, which explains why electronegativity increases from left to right across a period.