A compound contains 2 or more elements chemically combined.

Here's why:

* Elements are the simplest pure substances that cannot be broken down further by chemical means. Examples include oxygen (O), carbon (C), and hydrogen (H).

* Compounds are formed when two or more elements chemically combine in a fixed ratio. The resulting compound has properties different from the original elements. Examples include water (H₂O), carbon dioxide (CO₂), and table salt (NaCl).

Let me know if you'd like more examples!