Can I find chlorine in nature?
Well, the answer is yes and no. Since chlorine molecules are so very reactive, you will not find the free pure gas in nature. But scientists have identified several thousands of naturally-occurring chlorinated substances.
It starts, of course, with good old plain salt: its chemical formula is sodium chloride. We find massive quantities of it in the oceans and in salt mines, where former seas have deposited the salt. There is no “free chlorine” in salt, but it is widely used as a material to produce pure chlorine (Cl2). How is this chlorine produced? Read the section Working with salt, water and electrons and watch the animation on how to produce chlorine yourself!
Chlorine is widely found in nature in chlorinated substances, also called organochlorines. These are part of the wider substance family called organohalogens. More than 4000 of these natural ChlorineThings have been discovered and described. They are produced by natural phenomena like volcano eruptions, but also by hundreds of bacteria, fungi, marine organisms, insects, higher animals and… yes: humans. Your stomach contains one of the strongest acids: hydrogen chloride.