How does the atomic radius change from top to bottom in Groups 1 and 2?

Atomic radius increases from top to bottom in Groups 1 and 2

Explanation:

First we need to define Atomic radius;

Atomic radius is the distance from the nucleus of an atom to the outermost energy level. Group I and Group II of the periodic table are made up of alkali and alkaline-earth metal respectively.

Second, we identify the trend in the number of energy levels down the group

As you move down the group from top to the bottom, the number of energy levels of elements increases. For example, Lithium which is higher in group I has 2 energy levels while potassium which is lower in the group has three energy levels.

Third, we answer our question.

Therefore, the atomic radius increases from top to the bottom of a group due to an increase in the number of energy levels.