Chlorine is a naturally occurring element (#17 on the Periodic Table of the Elements). It occurs naturally in a wide variety of compounds, including many of the salts in the oceans. From these naturally occurring salts, elemental chlorine gas (Cl2) is produced through a manufacturing process. Want to know how chlorine was discovered or how it’s produced? The links below will take you to some detailed information regarding the science, manufacturing, transportation, and history of chlorine.