Answer:
Atomic radius increases from top to bottom in Groups 1 and 2
Step-by-step 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.