* Elements are the simplest pure substances that cannot be broken down further (like sodium and chlorine).

* Compounds are formed when two or more elements chemically combine in a fixed ratio. Table salt (NaCl) is formed by the chemical reaction of sodium (Na) and chlorine (Cl).

* Mixtures are combinations of two or more substances that are not chemically bonded and can be separated by physical means.

Since table salt is a chemical combination of sodium and chlorine, it's a compound.