Final answer:
NC13 is a compound that is not an ionic compound.
Step-by-step explanation:
Of the compounds listed, the only one that is not an ionic compound is NC13. Ionic compounds are formed between a metal and a nonmetal, where electrons are transferred from the metal atom to the nonmetal atom. Covalent compounds, on the other hand, are formed between nonmetals, where electrons are shared between atoms. In this case, NC13 is covalent because it is composed of nitrogen (a nonmetal) and chlorine (also a nonmetal).