Atomic Radius Trends in Group 1

The video tutorial addresses a class 10th chemistry problem about the periodic classification of elements, focusing on the atomic radii of Group 1 elements. It lists the atomic radii of sodium, potassium, rubidium, and cesium, and explains the observed trend that as we move down the group, the atomic radius increases. This is due to the increase in the number of electron shells, which increases the distance between the nucleus and the outermost orbit. The video concludes by reinforcing the concept that atomic radius increases down the group.

Which of the following elements has the smallest atomic radius in Group 1?

• Potassium

• Sodium

• Rubidium

• Cesium

Which element in Group 1 has an atomic radius of 244 picometers?

• Cesium

• Sodium

• Potassium

• Rubidium

What is the primary reason for the increase in atomic radius as you move down Group 1 elements?

• Decrease in nuclear charge

• Increase in the number of electron shells

• Decrease in electron affinity

• Increase in ionization energy

As you move down a group in the periodic table, what happens to the distance between the nucleus and the outermost electron shell?

• It fluctuates

• It remains the same

• It decreases

• It increases

What is the effect of increasing the number of electron shells on the atomic radius?

• It has no effect on the atomic radius

• It decreases the atomic radius

• It increases the atomic radius

• It makes the atomic radius unpredictable