Atomic Radius Trends in the Periodic Table

The video tutorial explains how to determine which of the two elements, calcium or magnesium, has a larger atomic radius. By examining the periodic table, it is shown that atomic radii decrease across periods and increase down groups. Calcium, being lower in the group than magnesium, has a larger atomic radius due to the addition of energy levels or shells as you move down the periodic table. The tutorial concludes that calcium is larger than magnesium.

Which two elements are being compared for their atomic radius in the video?

• Calcium and Magnesium

• Hydrogen and Helium

• Sodium and Potassium

• Iron and Copper

What happens to the atomic radius as you move across a period in the periodic table?

• It fluctuates randomly

• It remains the same

• It decreases

• It increases

How does the atomic radius change as you move down a group in the periodic table?

• It decreases

• It first increases then decreases

• It remains constant

• It increases

Why does calcium have a larger atomic radius than magnesium?

• Calcium has fewer electrons

• Calcium is lower in the group

• Calcium has more protons

• Calcium is higher in the group

What is added to an atom as you move down a group that causes the atomic radius to increase?

• Energy levels or shells

• Protons

• Electrons

• Neutrons

What is the main reason for the increase in atomic radius down a group?

• Decrease in atomic mass

• Addition of neutrons

• Addition of electron shells

• Addition of protons