Silver iodide and silver bromide photographic film.Betadine disinfectant contain iodopovidone C6H9I2NO.Iodine pellets and vapour in glass vial.Silver iodide is used in photographic film and in cloud seeding to modify rainfall. Iodine is used as a disinfectant and a radiocontrast material in medicine, and as a nutritional supplement. The element was named by Gay-Lussac, from Greek iode meaning violet, which is the colour of iodine vapour. This was followed by an announcement from Humphry Davy claiming it was a new element. In 1813 Joseph Louis Gay-Lussac announced that iodine was either a new element or an oxygen compound. Courtois suspected this was a new element and sent samples to other scientists to investigate. Iodine was first isolated by French chemist Bernard Courtois in 1811 from seaweed, in the process of extracting saltpeter for use in gunpowder for the Napoleonic Wars. Silver bromide AgBr – containing photographic film and photograph.
It is also used in photographic film in the form of silver bromide. The main application of bromine is in flame retardants. He originally named the element muride, after the Latin word for brine, but later changed it to brome after the Greek bromos meaning stench, to describe the smell of bromine vapour. He initially tried to prove it was iodine chloride but after failing to do so, he concluded that he had discovered a new element. Balard extracted bromine from seaweed that was used to produce iodine, and found that its properties were in between those of chlorine and iodine. The publication of his results was delayed, leading to Balard’s results being published first. Lowig extracted bromine from mineral water and submitted his discovery as part of a job application. Two scientists are credited with independently discovering bromine, Carl Jacob Lowig in 1825 and Antoine Balard in 1826. Polyvinyl chloride (PVC or vinyl) plastic pipes.Uses:Ĭhlorine compounds have a very large number of applications in industry in the production of organic compounds, plastics like polyvinyl chloride (PVC), for precursors used in the purification of metals, and as bleaches and disinfectants, such as in the sanitation of drinking water. The alternative name halogen was proposed, meaning salt-producer, but instead came to refer to the group to which chlorine belongs. 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. What elements are in Group 17 – Halides?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.
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