Quiz on Chlorine

Chlorine is a greenish-yellow gas with the chemical symbol Cl and atomic number 17. It belongs to Group 17 of the periodic table, known as the halogen group, which also includes fluorine and iodine. Chlorine has a strong, pungent smell and is toxic in high concentrations. It was first discovered in 1774 by Carl Wilhelm Scheele. Chlorine is highly reactive and forms chlorides when it combines with metals, such as sodium chloride (NaCl) — common table salt. One of its most important uses is in water purification and disinfection, as it kills bacteria and other harmful microorganisms. Chlorine is also used in the production of PVC (polyvinyl chloride) plastic, bleaching agents, and various chemical compounds. Although dangerous in pure form, when used safely, chlorine plays a vital role in maintaining hygiene and producing useful materials for modern life.