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 Pleasant Shade of Gray A Pleasant Shade of Gray A Pleasant Shade of Gray is a concept album by the progressive metal group Fates Warning, released in 1997. It contains one song divided into twelve parts and is noted for its darker mood and more progressive style. "A Pleasant Shade Of Gray" is a single song that is divided into twelve tracks. The album is notable for its darker mood and mixture of progressive rock and metal with hints of industrial, classical, and psychedelia. Jim Matheos wrote the album following Fates Warning's 1994 tour in support of "Inside Out", with Matheos mailing tapes to