Question

Which among the following has the highest ionic radius?
A. ${F^ - }$
B. ${B^{ + 3}}$
C. ${O_2}^{ - 2}$
D. $L{i^ + }$

Answer 1

Initially you should be aware of the radius of the ion Is calculated. Also, you must be aware of the ionic radius. You must know that it is the number of electrons which commands the ionic radius.

Complete step by step answer:
The ionic radius is not a fixed property of any given ion. Rather, it varies with coordination number, spin state, and other parameters. For our purposes, we are considering the ions to be as close to their ground state as possible. Nevertheless, ionic radius values are sufficiently transferable to allow periodic trends to be recognized
${F^ - }$ and ${O_2}^{ - 2}$ are isoelectronic species possessing 10 electrons each.
$L{i^ + }$ and ${B^{ + 3}}$ are isoelectronic species possessing 2 electrons each.
Since in the case of ${O_2}^{ - 2}$ , there is greater electron-electron repulsion and lesser effective nuclear charge, ${O_2}^{ - 2}$ has the largest ionic radius in this case.

So, the correct answer is Option C.

Note: Oxygen is just too chemically reactive to stay a free element in air without being continuously replenished by the photosynthetic action of living organisms. In a space lattice, the ionic radius may be a measure of the dimensions of the atom's ion.6 When formed, ionic atoms change in size with reference to their original atom. Cation radii will decrease and therefore the anion radii will increase in size compared to their neutral atoms.