Question

Which of the following has the highest cation to anion size ratio?

• A. $CsI$
• B. $CsF$
• C. $LiF$
• D. $LiI$

Answer 1

Answer: (B)

The cation to anion size ratio will be maximum when the cation is of largest size and the anion is of smallest size. Among the given species, $C{s}^{+}$ has maximum size among given cations and $F^{-}$ has smallest size among given anions, thus $CsF$ has highest $r_c/r_a$ ratio