Chlorine

Chlorine, a yellow-green gas at room temperature, is a chemical element with the symbol Cl and atomic number 17. This highly reactive non-metal is the second-lightest halogen, positioned between fluorine and bromine in the periodic table. Chlorine is an exceptionally strong oxidizing agent, exhibiting the greatest electron affinity among the elements and the third-highest electronegativity, surpassed only by oxygen and fluorine.