Answer :
Let's solve the problem step-by-step to understand the relationship between the atomic radii of beryllium and magnesium:
1. Understanding the Periodic Table Position:
- Beryllium and magnesium are both in Group 2 of the periodic table, also known as the alkaline earth metals.
- Beryllium is above magnesium on the periodic table, which means it has fewer electron shells. Specifically, beryllium is in Period 2, and magnesium is in Period 3.
2. General Trend in Atomic Radii:
- Within a group in the periodic table, as you move down from top to bottom (from lighter to heavier elements), the atomic radius generally increases. This is because each period down the group adds an extra electron shell.
- Consequently, as you move up a group (from heavier to lighter elements), the atomic radius decreases because there are fewer electron shells.
3. Applying the Trend to Beryllium and Magnesium:
- Since beryllium is above magnesium in the periodic table, it has fewer electron shells. Thus, according to periodic trends, beryllium should have a smaller atomic radius compared to magnesium.
4. Conclusion:
- Given that magnesium's atomic radius is 145 units, it is reasonable to conclude that beryllium's atomic radius is smaller than 145 units.
Therefore, the atomic radius of beryllium is smaller than 145 units.
1. Understanding the Periodic Table Position:
- Beryllium and magnesium are both in Group 2 of the periodic table, also known as the alkaline earth metals.
- Beryllium is above magnesium on the periodic table, which means it has fewer electron shells. Specifically, beryllium is in Period 2, and magnesium is in Period 3.
2. General Trend in Atomic Radii:
- Within a group in the periodic table, as you move down from top to bottom (from lighter to heavier elements), the atomic radius generally increases. This is because each period down the group adds an extra electron shell.
- Consequently, as you move up a group (from heavier to lighter elements), the atomic radius decreases because there are fewer electron shells.
3. Applying the Trend to Beryllium and Magnesium:
- Since beryllium is above magnesium in the periodic table, it has fewer electron shells. Thus, according to periodic trends, beryllium should have a smaller atomic radius compared to magnesium.
4. Conclusion:
- Given that magnesium's atomic radius is 145 units, it is reasonable to conclude that beryllium's atomic radius is smaller than 145 units.
Therefore, the atomic radius of beryllium is smaller than 145 units.
