Which of the alkali metals is the smallest in size?

Correct option is C

The correct answer is (c) Lithium.
· In the alkali metal group, the atomic size increases as you move down the group in the periodic table. This is because each element down the group has an additional electron shell, making the atoms larger.
· Lithium (Li) is the first element in the alkali metal group and has the smallest atomic size compared to the other alkali metals listed.
· As we move down the group from lithium to sodium, potassium, and rubidium, the atomic radius increases due to the addition of electron shells.
· Alkali metals include elements in Group 1 of the periodic table.
· They are highly reactive, especially with water, due to their single valence electron.
Additional Information:
· Potassium: Larger than lithium, sodium, and rubidium; it has more electron shells.
· Sodium: The second smallest among these, larger than lithium but smaller than potassium and rubidium.
· Lithium: The smallest in size, with only two electron shells, making it the correct answer.
· Rubidium: This is the largest among the options provided, as it is much further down the group.