It is used in chemistry to indicate the presence of chlorine atoms in a compound. For example:
* Chlorophyll: The green pigment in plants that absorbs light energy for photosynthesis.
* Chloroform: An organic compound used as a solvent and anesthetic.
* Chlorine gas: A yellowish-green gas used in water purification and as a chemical weapon.
The prefix "chloro" is derived from the Greek word "chloros," meaning "greenish-yellow." This is fitting, as chlorine gas has a greenish-yellow color.