Atomic Radius Trends
Atomic Radius is the size of an atom, or in other words, the distance from the center of the nucleus to its outermost electron on the outermost shell. Atomic Radius might be hard to understand, so in a simpler way, Atomic Radius is similar to the radius of a circle. The center of the circle is the nucleus and the outer edge of the circle is the outermost shell. It is difficult to pinpoint the Atomic Radius, but these trends can be identified in the Periodic Table:
This is because as you go down a group you basically add another "shell" to the Bohr Diagram, therefore adding distance to the radius. The Atomic Radius decreases from left to right because the more you go right the more protons you will add. And as we know, Protons pull and attract electrons on the shells. Therefore, the more protons present, the higher the pull, which results into a lower Atomic Radius.
- Atomic Radius increases going down the periodic table
- Atomic Radius decreases going from left to right of the periodic table.
This is because as you go down a group you basically add another "shell" to the Bohr Diagram, therefore adding distance to the radius. The Atomic Radius decreases from left to right because the more you go right the more protons you will add. And as we know, Protons pull and attract electrons on the shells. Therefore, the more protons present, the higher the pull, which results into a lower Atomic Radius.
Watch this video to learn more about Atomic Radius: