Solid $CO_2$ is an example of which type of crystal?

Which substance is an example of a network solid?

The ionic radii of $Rb^{+}$ and $I^{-}$ are $1.46 \ \mathring{A}$ and $2.16 \ \mathring{A}$,respectively. The most probable type of structure exhibited by it is:

Explain the repulsive forces between two molecules.

Which among the following molecules exhibits strong London forces?

Suggest the most important type of intermolecular attractive interaction in the following pairs.
$(i)$ $n$-hexane and $n$-octane
$(ii)$ $I_{2}$ and $CCl_{4}$
$(iii)$ $NaClO_{4}$ and water
$(iv)$ methanol and acetone
$(v)$ acetonitrile $(CH_{3}CN)$ and acetone $(C_{3}H_{6}O)$