Final answer:
Option A: LiCl, or lithium chloride, is the ionic compound among the provided options because it's composed of a metal and a nonmetal, which is a characteristic of ionic compounds.
Step-by-step explanation:
The ionic compound from the options provided is A. LiCl, which stands for lithium chloride. An ionic compound is formed when one atom transfers electrons to another atom, typically between a metal and a nonmetal. In the case of LiCl, lithium (Li) is a metal and chlorine (Cl) is a nonmetal, making their combination an ionic compound. The other options, B. CO, C. NO₂, and D. SO₃_are examples of covalent compounds where the atoms share electrons rather than transferring them.
The option that is an ionic compound is option A, LiCl. Ionic compounds are formed when a metal cation binds with a nonmetal anion through electrostatic attraction. In this case, lithium (Li) is a metal cation, and chlorine (Cl) is a nonmetal anion. Therefore, LiCl is an example of an ionic compound.