How does electronegativity vary across the periodic table?

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond. Understanding how electronegativity changes across the periodic table is crucial for predicting how atoms will interact with one another in chemical reactions.

Electronegativity increases from left to right across a period. This trend occurs because, as you move from left to right, atoms have more protons in their nuclei. The increased positive charge leads to a stronger attraction between the nucleus and the electrons, raising the electronegativity of the elements.

Additionally, electronegativity decreases from top to bottom within a group. As you move down a group, the number of electron shells increases, which places the valence electrons further from the nucleus. This increased distance reduces the nucleus' ability to attract electrons, resulting in lower electronegativity.

Therefore, the overall trend is that electronegativity increases from left to right across a period and decreases from top to bottom in a group, making the correct option one that accurately captures this relationship.