Question

What is the difference between the Ionic radius of cations of Lithium and magnesium?

(a) 2 A°

(b) 0.05 A°

(c) 1 A°

(d) 5 A°

This question was addressed to me in quiz.

The origin of the question is s-Block Elements in chapter s-Block Elements of Chemistry – Class 11

Answer 1

The correct choice is (b) 0.05 A°

For explanation I would say: The Ionic radius of Lithium cation is 0.60A°, which is very close to that of magnesium cation that is 0.65A°, therefore the difference between the Ionic radius of cations of Lithium and magnesium is 0.05A°.