H2O (water), CO2 (carbon dioxide), and NaCl (sodium chloride) are all examples of compounds.

Here's why:

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

* H2O is formed from two hydrogen atoms and one oxygen atom.

* CO2 is formed from one carbon atom and two oxygen atoms.

* NaCl is formed from one sodium atom and one chlorine atom.

Let me know if you'd like to know more about compounds!