Which statement best describes the trend in electronegativity values across a period in the periodic table?

• A. Electronegativity decreases from left to right across a period.
• B. Electronegativity increases from left to right across a period.
• C. Electronegativity first increases and then decreases across a period.
• D. Electronegativity remains constant across a period.

Answer: (B)

Verified step by step guidance

1. Understand that electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond.
2. Recall the periodic trend that electronegativity generally changes as you move across a period (row) in the periodic table from left to right.
3. Recognize that as you move from left to right across a period, the number of protons in the nucleus increases, which increases the nuclear charge.
4. Because the nuclear charge increases while the shielding effect remains relatively constant across a period, the effective nuclear attraction on the valence electrons increases.
5. Conclude that this increased attraction causes electronegativity to increase from left to right across a period.