Here's why:

* Elements are the simplest pure substances that cannot be broken down into simpler substances by chemical means. They are found on the periodic table.

* Compounds are formed when two or more elements combine chemically in a fixed ratio.

Chlorine (Cl) appears on the periodic table as a single, uncombined atom. It exists naturally as a diatomic molecule (Cl₂), but this is still considered the same element.