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
A Shade of Difference in southern states. "Advise and Consent" and its sequels had been out of print for almost 15 years until WordFire Press reissued them in paperback and e-book format in 2014. A Shade of Difference A Shade of Difference () is a 1962 political novel written by Allen Drury. It is the first sequel to "Advise and Consent", for which Drury was awarded the Pulitzer Prize for Fiction in 1960, and was followed in 1966 by "Capable of Honor". The novel focuses on the politics among delegations to the United Nations and the troubles that Third World nations cause the United