Final answer:
The compound that is not considered covalent (i.e., molecular) among the given options is NaF.
Step-by-step explanation:
The compound that is not considered covalent (i.e., molecular) among the given options is B. NaF.
Compounds that are composed of a metal and a non-metal, like NaF, display ionic bonding. Ionic bonds are formed when one atom donates an electron to another, resulting in a strong electrostatic attraction between the positively charged metal cation and the negatively charged non-metal anion.
In contrast, covalent bonding occurs when two non-metals share electrons to form a molecule, which is the case for the other compounds listed: SiF4 (A), N2S3 (C), and Br2 (D).