Sodium chlorine is not a valid chemical term. You're likely thinking of sodium chloride, which is a compound.

Here's why:

* Elements are pure substances made up of only one type of atom (like sodium or chlorine).

* Compounds are formed when two or more elements chemically combine in a fixed ratio (like sodium chloride, NaCl).

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

Sodium chloride (NaCl) is formed by the chemical reaction of sodium (Na) and chlorine (Cl) in a 1:1 ratio.