Ionization energy is an interesting topic when we look at how it changes on the periodic table. Let's break it down:

Across a Period:

• Increases Left to Right: As you move from the left side to the right side of a row, the ionization energy goes up. This happens because the number of protons, which are positively charged, increases. More protons mean a stronger pull on the electrons, making it harder to take an electron away.

Down a Group:

• Decreases Going Down: When you move down a column, the ionization energy goes down. This is because the outer electrons are farther away from the nucleus. Plus, they are blocked by the inner electrons, which makes it easier to remove an outer electron.

So, to sum it up: ionization energy gets higher as you go across a period and lower as you go down a group! It's all about how strong the positive charge is and how far the electrons are from the center.