Chlorine
Chlorine, is a chemical element with atomic number 17 and Cl symbol. It is a halogen, found in a periodic table in group 17. As chloride ions, which are part of ordinary salts and other compounds, naturally it is abundant and indispensable in many forms of life, including humans. As a gas chlorine, it is yellowish green, which weighs two and a half times while its smell is very toxic and very toxic. In the form of liquid and solid it is an effective oxidation, bleaching, and non-repellent agent.