The names of the elements that combine to form a compound are listed in its chemical formula.

For example:

* Water (H₂O) is formed by the elements hydrogen (H) and oxygen (O).

* Sodium chloride (NaCl) is formed by the elements sodium (Na) and chlorine (Cl).

* Carbon dioxide (CO₂) is formed by the elements carbon (C) and oxygen (O).

The chemical formula tells you not only the elements involved but also the ratio in which they combine. For instance, in water, there are two hydrogen atoms for every one oxygen atom.