Question

Which of the following has the highest percentage of ionic character?

• A. $LiI$
• B. $MgC{l}_2$
• C. $CsF$
• D. $CsI$

Answer 1

The correct option is C $CsF$

For a compound to be ionic, the cation should have less polarising power and the anion should have the least polarisability.

Here, $C{s}^{+}$ ion is large and hence has less polarising power, and $F^{-}$ ion is small and has the least polarisability.

Size of cations: $L{i}^{+}<M{g}^{2+}<C{s}^{+}$

Size of anions :$F^{-}<C{l}^{-}<I^{-}$

Hence, the highest $\%$ of ionic character is exhibited by $CsF$.