Period 3 element in 1810, who named it chlorine, from the Greek word χλωρος (chlōros), meaning "green-yellow." Chlorine is a component of various compounds, including table salt. It is the second most abundant halogen and 21st most abundant chemical element in Earth's crust. The great oxidizing potential of chlorine led it to its bleaching and disinfectant uses, as well as uses of an essential reagent in the chemical industry. As a common disinfectant, chlorine compounds are used in swimming pools to keep them clean and sanitary. In the upper atmosphere, chlorine-containing molecules such as chlorofluorocarbons have been implicated in ozone depletion. "Argon" (symbol
Organisation for the Prohibition of Chemical Weapons Organisation for the Prohibition of Chemical Weapons The Organisation for the Prohibition of Chemical Weapons (OPCW) is an intergovernmental organisation and the implementing body for the Chemical Weapons Convention, which entered into force on 29 April 1997. The OPCW, with its 193 member states, has its seat in The Hague, Netherlands, and oversees the global endeavour for the permanent and verifiable elimination of chemical weapons. The organisation promotes and verifies the adherence to the Chemical Weapons Convention, which prohibits the use of chemical weapons and requires their destruction. Verification consists both of evaluation of declarations by member states and onsite