What happens to the atomic radius as you move right, as you move up? What affects the size of the atoms when you move up and down a family? What affects the size as you move left and right in a period? What has a greater effect, moving up and down, or moving left and right? Why?

As you move right on the periodic table, the atomic radius decreases. Also, as you move from bottom to top of the groups on the periodic table the size of the radius becomes smaller.


When you move up and down a family on the periodic table, there are more layers of electrons being added to the outer shell of an element as you go from top to bottom.


Going from left to right on the periodic table, elements gain protons in the nucleus. This increasing positive charge pulls the shell of the atom in toward the nucleus, thus making the atomic radius slightly smaller.

Moving left to right on the periodic table has more of an effect on elements than moving up and down. It produces more drastic changes because the number of protons in the elements are changing and affecting their charges.

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