Chlorine is a highly reactive chemical element with the symbol Cl and atomic number 17. It exists as a diatomic gas with a distinct, pungent odor and is widely known for its role as a disinfectant and bleaching agent. Chlorine is extensively used in water treatment to kill bacteria and make drinking water safe, and it plays a crucial role in sanitizing swimming pools. Additionally, it is a key component in the production of a wide range of chemicals, including plastics, solvents, and pesticides. Chlorine's versatile properties and ability to disinfect and oxidize contaminants make it an invaluable resource in public health, industry, and various chemical processes.