Question

In which of the following compounds is the size of cation to anion ratio maximum?

• A. CsF
• B. LiI
• C. LiF
• D. CsI

Answer 1

The correct option is B LiI

Within a group the size of the element increases from top to bottom. Therefore size of $L{i}^{+}$ < $C{s}^{+}$ and $F^{-}$<$I^{-}$.

For a maximum ratio of cation to anion size, smaller cation and larger anion should be used. Therefore $LiI$ is the answer.

Hence, the correct option is $\text{B}$