Answer
SiCl$_{4}$, B$_{2}$H$_{6}$, and C$_{2}$H$_{4}$ are likely to be molecular compounds.
LiF, BaCl$_{2}$, and KCl are likely to be ionic compounds.
Work Step by Step
SiCl$_{4}$, B$_{2}$H$_{6}$, and C$_{2}$H$_{4}$ are likely to be molecular compounds because they are compounds between two nonmetal elements. Nonmetal elements usually don't transfer electrons to one another; usually, the electrons are shared between the atoms.
LiF, BaCl$_{2}$, and KCl are likely to be ionic compounds because they involve bonds between a metal and nonmetal. Metals usually are electron donors and nonmetals are usually electron acceptors; therefore, metals form cations and nonmetals form anions. It is this attraction between positive and negative charges that forms ionic bonds.
