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

• A. Electronegativity remains constant across periods and groups.
• B. Electronegativity increases from left to right across a period and decreases from top to bottom down a group.
• C. Electronegativity increases from left to right across a period and increases from top to bottom down a group.
• D. Electronegativity decreases from left to right across a period and increases from top to bottom down a group.

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 general trend of electronegativity across a period (left to right) in the periodic table: as you move from left to right, the number of protons in the nucleus increases, which increases the effective nuclear charge and pulls electrons closer, thus increasing electronegativity.
3. Recall the general trend of electronegativity down a group (top to bottom): as you move down a group, additional electron shells are added, increasing the distance between the nucleus and the valence electrons, which reduces the nucleus's pull on bonding electrons, thus decreasing electronegativity.
4. Combine these observations to conclude that electronegativity increases from left to right across a period and decreases from top to bottom down a group.
5. Use this understanding to evaluate the given statements and identify the one that correctly describes the trend in electronegativity.