Electronegativity is a helpful idea that shows us how atoms act when they bond with each other. Let's break down how it changes across the periodic table:

1. Gets Stronger Across Periods: As you move from left to right in a row of the periodic table, electronegativity gets stronger. This happens because the atom's positive charges (nuclear charges) increase, which pulls the electrons they share closer to them.

2. Gets Weaker Down Groups: If you go down a column in the table, electronegativity gets weaker. Why does this happen? As you go down, atoms get bigger, and the electrons on the outside are farther away from the positive center. This makes it harder for them to attract other electrons.

3. Guessing How Atoms Will Act: Atoms with high electronegativity, like fluorine, are better at attracting electrons. This makes them good at reacting with other elements. On the other hand, atoms with low electronegativity, like cesium, tend to lose their electrons easily and are not as good at attracting them.

By understanding these patterns, we can better guess how different elements will work together in chemical reactions!