The following year Sir Humphry Davy concluded that it is an element, which he named chlorine from the Greek chloros meaning pale green-yellow, which is the colour of chlorine gas. In 1809, Joseph Gay-Lussac and Louis-Jacques Thenard tried to release muriaticum from muriatic acid air and failed, raising the possibility that it was itself an element. Scheele failed to recognise it as an element and it was eventually believed to be an oxide of the hypothetical element muriaticum. Polytetrafluorethylene (PTFE or Teflon) tape, tube used in medical devices, and rod.Ĭhlorine compounds like salt have been used since ancient times, and chlorine gas was produced from the 1200s as a by-product of acid production, however its discovery as an element began in 1774 when Carl Wilhelm Scheele produced chlorine gas and called it dephlogisticated muriatic acid air.Fluorine is also used in uranium enrichment and in refrigerants (CFCs) though the latter have been phased out as they damage the ozone layer. Fluorine salts are used in tap water and toothpaste to prevent tooth decay. The fluorine-containing polymer PTFE (Teflon) is used in electrical insulation, medical devices and cookware.
Uses:įluorine compounds are still used in the processing of metals. Although experiencing serious poisoning, Henri Moissan was the first to successfully isolate fluorine gas in 1886. Several scientists then attempted to isolate fluorine from hydrofluoric acid, but were either injured or killed by it, as it is a very toxic substance. Andre Marie Ampere proposed in 1810 that this acid consisted of hydrogen and another element similar to chlorine, and Sir Humphry Davy named this new element fluorine, combining fluo- from the name of the acid and the -ine suffix used in naming halogens. In the 18th century hydrofluoric acid (then called fluorspar acid), made from fluorite, was used in glass etching. It was named fluores after the Latin word fluor, meaning flow. Together with groups 13-16 and 18, they form the p-block.Ĭlick on the following elements to learn more about them:įluorite (CaF 2) was used in the 16th century in the processing of metals as an additive to lower their melting points and make them easier to process. Reactivity decreases down the group, with fluorine being the most reactive. They are all non-metals, and form anions with a -1 charge. Group 17 is the halogens, they have 7 electrons in their outermost shell. Why are the elements in Group 17 categorised together? In this article, we give you the history and uses for the elements in Group 17 – Halides.
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