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

• A. Because metallic character increases, leading to a greater tendency to attract electrons.
• B. Because the number of energy levels increases, making it easier for atoms to attract electrons.
• C. Because atoms gain more protons and electrons, which always makes them more electronegative regardless of their position.
• D. Because atomic radius decreases and nuclear charge increases, causing a stronger attraction for bonding electrons.

Answer: (D)

Verified step by step guidance

1. Understand that electronegativity is the measure of an atom's ability to attract and hold onto electrons in a chemical bond.
2. Recognize that as you move across a period from left to right, the number of protons in the nucleus (nuclear charge) increases, which means the positive charge attracting electrons becomes stronger.
3. Note that the number of energy levels (electron shells) remains the same across a period, so the electrons are held closer to the nucleus without additional shielding from inner shells.
4. Because the atomic radius decreases across a period, the bonding electrons are closer to the nucleus and experience a stronger pull due to the increased nuclear charge.
5. Combine these factors to conclude that the stronger nuclear attraction and smaller atomic radius cause electronegativity to increase as you move from left to right across a period.