Chlorine is a chemical element with the symbol Cl and atomic number 17. It is a greenish-yellow gas at room temperature and is known for its strong, pungent smell. Chlorine is commonly used in swimming pools to kill bacteria and keep the water clean. It is also an important ingredient in many household cleaning products. In nature, chlorine is found in various compounds, such as sodium chloride, which is table salt. It plays a vital role in the production of plastics, especially PVC, and is used in the manufacturing of disinfectants and bleaches. Chlorine is essential for maintaining hygiene and safety in many everyday products.