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
Westward the Course of Empire Takes Its Way Westward the Course of Empire Takes Its Way Westward the Course of Empire Takes Its Way (also known as Westward Ho) is a painted mural displayed behind the western staircase of the House of Representatives chamber in the United States Capitol Building. The mural was painted by Emanuel Gottlieb Leutze in 1861 and symbolizes Manifest Destiny, the belief that the United States was destined for Western exploration and expansion originating from the initial colonies along the Atlantic seaboard to the Pacific Ocean. A study measuring hangs in the Smithsonian American Art Museum. The darkness turning into light represents the greatness