Which of the following best describes the periodic trend for electronegativity across the periodic table?

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

Answer: (A)

Verified step by step guidance

1. Step 1: Understand what electronegativity means. Electronegativity is the tendency of an atom to attract electrons towards itself when it forms a chemical bond.
2. Step 2: Recall the general trend of electronegativity across a period (left to right) in the periodic table. As you move from left to right across a period, the number of protons in the nucleus increases, which increases the nuclear charge and pulls electrons closer, increasing electronegativity.
3. Step 3: Recall the general trend of electronegativity down a group (top to bottom). As you move down a group, atoms have more electron shells, which increases the distance between the nucleus and the valence electrons, reducing the effective nuclear attraction and thus decreasing electronegativity.
4. Step 4: Combine these two trends to describe the overall pattern: electronegativity increases from left to right across a period and decreases from top to bottom down a group.
5. Step 5: Use this understanding to evaluate the given options and select the one that correctly states this trend.