Which one of the following ions has the highest value of ionic radius

• Periodic Properties

Which one of the following ions has the highest value of ionic radius?

1. Li⁺
2. F^–
3. O^2–
4. B³⁺

Answer

This can be explained on the basis of z/e, where as z/e ratio increases, the size decreases and when z/e ratio decreases the size increases.

z is atomic number and e is number of electrons.

For Li⁺, z/e = 3/2 = 1.5

For F^-, z/e = 9/10 = 0.9

For O^2-, z/e = 8/10 = 0.8

For B³⁺, z/e = 5/2 = 2.5

The correct option is C.