Chlorine is an element with the symbol Cl and the atomic number of 17. At room temperature, it appears as a yellow-green gas, and it is classed as a halogen. How many of these chlorine facts did you know?
- While there are records of chlorine being known for hundreds of years, it wasn’t until 1810 that it was confirmed to be a pure element: This confirmation was achieved by chemist Sir Humphry Davy.
- Sir Humphry Davy was a prolific chemist in terms of making discoveries of new elements: He is also credited with the discovery of sodium, pottasium, barium, calcium, strontium and magnesium.
- The name chlorine is derived from the ancient Greek word khlôros, which means pale green: This is a reference to the fact that chlorine gas is green in color.
- Sodium chloride is the most common compound of chlorine, and it has been used by humans for thousands of years: There is evidence of prehistoric humans using it as early as 6000 BC.
- While Sir Humphry Davy was the first to confirm chlorine as a pure element, Carl Wilhelm Scheele studied it in detail over 30 years earlier: However, he failed to identify it as a pure element. Scheele is, however, credited with the being the first chemist to identify tungsten.
- Chlorine gas would be used with devastating consequences during World War I: The German Army first used it in 1915, and it had a serious impact on soliders exposed to it.
- However, in small doses, chlorine can actually be a useful thing for humankind: From 1918, chlorine began to be added to disinfect drinking water and kill bacteria in the United States.
- Chlorine remains an important chemical for use in purifying water and treating swimming pools: In some rare cases, though, chlorine has been linked to the collapse of swimming pools after it reacted with suspension rods.
- Chlorine has a lot in common with the other halogens, namely fluorine, bromine, and iodine: Out of all the halogen, chlorine is second only to flourine in terms of how strong an oxidising agent it is.
- While chlorine gas is a yellow/greenish color at room temperature, the color changes drastically based on its temperature: The colder it gets, the fainter the color becomes, and it is completely transparent at −195 °C.