{"id":16100,"date":"2024-08-30T08:52:25","date_gmt":"2024-08-30T06:52:25","guid":{"rendered":"https:\/\/www.rct-online.de\/magazin\/?p=16100"},"modified":"2026-02-24T12:59:14","modified_gmt":"2026-02-24T11:59:14","slug":"uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute","status":"publish","type":"post","link":"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/","title":{"rendered":"Uses and Properties of the Halogens \u2013 What Fluorine, Chlorine &#038; Co. Contribute"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_73 ez-toc-wrap-center counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#What_Are_Halogens\" title=\"What Are Halogens?\">What Are Halogens?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#History_and_Discovery_of_the_Halogens\" title=\"History and Discovery of the Halogens\">History and Discovery of the Halogens<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#Production_of_Halogens\" title=\"Production of Halogens\">Production of Halogens<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#Properties_of_the_Halogens\" title=\"Properties of the Halogens\">Properties of the Halogens<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#Important_Halogen_Compounds\" title=\"Important Halogen Compounds\">Important Halogen Compounds<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#Applications_of_Halogens\" title=\"Applications of Halogens\">Applications of Halogens<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.rct-online.de\/magazin\/en\/uses-and-properties-of-the-halogens-what-fluorine-chlorine-co-contribute\/#Halogens_in_Everyday_Life\" title=\"Halogens in Everyday Life\">Halogens in Everyday Life<\/a><\/li><\/ul><\/nav><\/div>\n<p style=\"text-align: justify;\"><strong>When hearing the term \u201chalogen,\u201d many people first think of lamps or headlights. However, halogens are found in numerous products we use every day. This article explains what halogens are and where they are applied.<\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_Are_Halogens\"><\/span>What Are Halogens?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"box info  \"><div class=\"box-inner-block\"><i class=\"fa tie-shortcode-boxicon\"><\/i>\n\t\t\tThe term halogens refers to the elements of Group 17 of the periodic table. This group is located between Group 16 (the chalcogens) and Group 18 (the noble gases). Group 17 includes the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).\n\t\t\t<\/div><\/div>\n<p style=\"text-align: justify;\">The name \u201chalogen\u201d is derived from the Greek words <em>\u201chals\u201d<\/em> (salt) and <em>\u201cgennan\u201d<\/em> (to produce), reflecting their ability to form salts when reacting with metals.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"History_and_Discovery_of_the_Halogens\"><\/span>History and Discovery of the Halogens<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"text-align: justify;\">The halogens were discovered in the order chlorine, iodine, bromine, and fluorine. When the German chemist and pharmacist Carl Wilhelm Scheele (1742\u20131786) first produced chlorine, it was initially believed to be an oxygen compound. In 1808, the English chemist Sir Humphry Davy (1778\u20131829) recognized it as a new element. Due to its yellow-green color, he named it after the Greek word <em>\u201cchloros\u201d<\/em>, meaning yellow-green.<\/p>\n<figure id=\"attachment_16106\" aria-describedby=\"caption-attachment-16106\" style=\"width: 1000px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-16106 size-full\" title=\"The halogens are located in Group 17 of the periodic table\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2024\/08\/Periodic-Table-of-Elements.jpg\" alt=\"The halogens are located in Group 17 of the periodic table\" width=\"1000\" height=\"593\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2024\/08\/Periodic-Table-of-Elements.jpg 1000w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2024\/08\/Periodic-Table-of-Elements-300x178.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2024\/08\/Periodic-Table-of-Elements-768x455.jpg 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><figcaption id=\"caption-attachment-16106\" class=\"wp-caption-text\"><center>The halogens are located in Group 17 of the periodic table<\/center><\/figcaption><\/figure>\n<p style=\"text-align: justify;\">Iodine was discovered in 1812 in the ash of seaweed and was named after the Greek word <em>\u201cioeides\u201d<\/em>, meaning violet-colored, referring to the purple color of its vapor.<\/p>\n<p style=\"text-align: justify;\">In 1826, the French chemist Antoine-J\u00e9r\u00f4me Balard (1802\u20131876) extracted bromine from seaweed and was the first to recognize it as a new element. Two years earlier, Justus von Liebig (1803\u20131873) had found bromine while analyzing salt brines but mistakenly assumed it to be a chlorine-iodine compound. Balard is therefore regarded as the discoverer of bromine. The element was named after the Greek word <em>\u201cbromos\u201d<\/em> (stench) due to its pungent odor.<\/p>\n<p style=\"text-align: justify;\">The mineral fluorspar, calcium fluoride (CaF<sub>2<\/sub>), had been known since the 16th century and was added during ore smelting because it made slag more fluid. Due to its high reactivity and toxicity, elemental fluorine was not successfully isolated until 1886 by the French chemist Ferdinand Fr\u00e9d\u00e9ric Henri Moissan (1852\u20131907), who received the Nobel Prize in Chemistry in 1906 for this achievement. The element\u2019s name is derived from the Latin word <em>\u201cfluor\u201d<\/em>, meaning flow.<\/p>\n<p style=\"text-align: justify;\">Radioactive astatine is the rarest naturally occurring chemical element. In 1940, it was artificially produced by the Americans Dale Corson, Kenneth MacKenzie, and Emilio Gino Segr\u00e8 at the University of California using a particle accelerator. Three years later, the element with atomic number 85 was named astatine, derived from the Greek <em>\u201castatos\u201d<\/em>, meaning unstable.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Production_of_Halogens\"><\/span>Production of Halogens<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"text-align: justify;\">Elemental fluorine (F<sub>2<\/sub>) can only be produced by electrolysis of hydrogen fluoride. Since hydrogen fluoride has low electrical conductivity, a mixture of hydrogen fluoride and potassium fluoride is used to increase conductivity. The process must be completely water-free; otherwise, oxygen would form at the anode instead of fluorine.<\/p>\n<figure id=\"attachment_10285\" aria-describedby=\"caption-attachment-10285\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-10285 size-full\" title=\"Coloration of the four stable halogens fluorine, chlorine, bromine and iodine\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/farbgebung-der-halogene.jpg\" alt=\"Coloration of the four stable halogens fluorine, chlorine, bromine and iodine\" width=\"450\" height=\"338\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/farbgebung-der-halogene.jpg 450w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/farbgebung-der-halogene-300x225.jpg 300w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption id=\"caption-attachment-10285\" class=\"wp-caption-text\"><center>Coloration of the four stable halogens fluorine, chlorine, bromine and iodine<\/center><\/figcaption><\/figure>\n<p style=\"text-align: justify;\">Chlorine is primarily produced from an aqueous sodium chloride solution by the chlor-alkali electrolysis process. The reaction products are chlorine (Cl<sub>2<\/sub>), hydrogen (H<sub>2<\/sub>), and sodium hydroxide (NaOH). Bromine is obtained by reacting bromides\u2014extracted from salt deposits or seawater\u2014with chlorine. Iodine is produced from iodate (IO<sub>3<\/sub><sup>&#8211;<\/sup>) formed in the mother liquor during nitrate production. The iodate solution is treated with sulfurous acid (H<sub>2<\/sub>SO<sub>3<\/sub>), forming hydrogen iodide, which then reacts with iodic acid (HIO<sub>3<\/sub>) present in the solution to yield elemental iodine.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Properties_of_the_Halogens\"><\/span>Properties of the Halogens<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"box success  \"><div class=\"box-inner-block\"><i class=\"fa tie-shortcode-boxicon\"><\/i>\n\t\t\tHalogens are non-metals. They possess seven outer-shell electrons (valence electrons) and therefore require only one additional electron to achieve a stable noble gas configuration. For this reason, they are highly reactive and occur in nature only in compounds. In their elemental form, they exist as diatomic molecules (F<sub>2<\/sub>, Cl<sub>2<\/sub>, I<sub>2<\/sub>).\n\t\t\t<\/div><\/div>\n<p style=\"text-align: justify;\">Fluorine has the highest electronegativity and reactivity. As the atomic number increases from fluorine to iodine, physical properties change: density, melting point, boiling point, and color intensity increase. Under standard conditions (0 \u00b0C, 1 bar), fluorine and chlorine are gases, bromine is liquid, and iodine is solid. Astatine is radioactive and decays; its longest-lived isotope, <sup>210<\/sup>At, has a half-life of 8.3 hours. Fluorine is pale yellow-green, chlorine greenish, bromine brown, iodine gray-black, and iodine vapor violet. Water solubility and reactivity decrease with increasing atomic number.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Important_Halogen_Compounds\"><\/span>Important Halogen Compounds<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"text-align: justify;\">When reacting with metals, halogens form salts known as halides. These salts\u2014fluorides, chlorides, bromides, and iodides\u2014consist of metal cations and halide anions. They have high melting and boiling points and are electrical insulators in solid form. In aqueous solution or when molten, they conduct electricity.<\/p>\n<p style=\"text-align: justify;\">Halogens react with hydrogen to form hydrogen halides. Hydrogen chloride, hydrogen bromide, and hydrogen iodide are gaseous under standard conditions, with boiling points decreasing as atomic number increases. Hydrogen fluoride forms strong hydrogen bonds and is therefore liquid under standard conditions. The aqueous solutions of hydrogen halides are called hydrohalic acids. Common names include hydrofluoric acid and hydrochloric acid. Hydriodic acid is considered the strongest oxygen-free <a href=\"https:\/\/www.rct-online.de\/magazin\/en\/acids-and-bases-in-everyday-life\/\">acid<\/a>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Applications_of_Halogens\"><\/span>Applications of Halogens<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"text-align: justify;\">Elemental fluorine is used to produce fluorinated compounds that cannot be manufactured by other methods. One example is polytetrafluoroethylene (PTFE), which is processed into breathable textiles and non-stick coatings. In chemical engineering, PTFE is valued as a chemically inert and temperature-resistant material and is processed into <a href=\"https:\/\/www.rct-online.de\/en\/tubes-hoses\/tubings-and-pipes-made-of-rigid-plastics\/ptfe-tubing\">PTFE hoses<\/a>, <a href=\"https:\/\/www.rct-online.de\/en\/seals-and-gaskets\">seals<\/a>, <a href=\"https:\/\/www.rct-online.de\/en\/tube-hose-connectors\/connectors-made-of-plastic\">hose connectors<\/a>, and other components.<\/p>\n<p><a href=\"https:\/\/www.rct-online.de\/en\/tubes-hoses\/tubings-and-pipes-made-of-rigid-plastics\/fep-tubing\/28715\/fep-chemical-tubing\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-10287 size-medium\" title=\"FEP Chemical Tubing\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/fep-chemieschlauch-300x300.jpg\" alt=\"FEP Chemical Tubing\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/fep-chemieschlauch-300x300.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/fep-chemieschlauch-150x150.jpg 150w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/fep-chemieschlauch.jpg 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a> <a href=\"https:\/\/www.rct-online.de\/en\/tubes-hoses\/tubings-and-pipes-made-of-rigid-plastics\/ptfe-tubing\/28770\/ptfe-chemical-tubing-standard\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-10288 size-medium\" title=\"PTFE Chemical Tubing - standard\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-chemieschlauch-standard-1-300x300.jpg\" alt=\"PTFE Chemical Tubing - standard\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-chemieschlauch-standard-1-300x300.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-chemieschlauch-standard-1-150x150.jpg 150w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-chemieschlauch-standard-1.jpg 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p style=\"text-align: justify;\">The majority of produced fluorine is used in nuclear technology. Natural uranium contains three isotopes (<sup>234<\/sup>U, <sup>235<\/sup>U, and <sup>238<\/sup>U), of which only <sup>235<\/sup>U is suitable for nuclear fission. Uranium reacts with fluorine to form gaseous uranium hexafluoride (UF<sub>6<\/sub>), allowing isotope separation by gas centrifuges due to slight mass differences.<\/p>\n<p style=\"text-align: justify;\">Chlorine is an essential raw material in the chemical industry. In inorganic chemistry, hydrochloric acid, chlorides, hypochlorites, and chlorates are produced from chlorine. In organic chemistry, it is used to synthesize compounds such as vinyl chloride\u2014the precursor for <a href=\"https:\/\/www.rct-online.de\/en\/tubes-hoses\/tubing-made-of-elastomers-soft-rubber\/pvc-tubing-tygon-tubing\">PVC hoses<\/a>\u2014or epichlorohydrin. Chlorine is also used in the synthesis of chlorine-free compounds produced via chlorine-containing intermediates. Additionally, chlorine\u00a0serves as an oxidizing, bleaching, and disinfecting agent and is present in many pharmaceuticals. In the past, chloroform (CHCl<sub>3<\/sub>) was used as an anesthetic.<\/p>\n<p><a href=\"https:\/\/www.rct-online.de\/en\/tubes-hoses\/tubing-made-of-elastomers-soft-rubber\/pvc-tubing-tygon-tubing\/28644\/pvc-chemical-tubing-metric\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-10289 size-medium\" title=\"PVC Chemical Tubing - metric\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-chemieschlauch-metrisch-300x300.jpg\" alt=\"PVC Chemical Tubing - metric\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-chemieschlauch-metrisch-300x300.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-chemieschlauch-metrisch-150x150.jpg 150w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-chemieschlauch-metrisch.jpg 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a> <a href=\"https:\/\/www.rct-online.de\/en\/tubes-hoses\/tubing-made-of-elastomers-soft-rubber\/pvc-tubing-tygon-tubing\/28662\/pvc-spiral-industrial-tubing\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-10291 size-medium\" title=\"PVC Spiral Industrial Tubing\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-spiral-industrieschlauch-300x300.jpg\" alt=\"PVC Spiral Industrial Tubing\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-spiral-industrieschlauch-300x300.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-spiral-industrieschlauch-150x150.jpg 150w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/pvc-spiral-industrieschlauch.jpg 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p style=\"text-align: justify;\">Bromine is used in the production of disinfectants, insecticides and pesticides, and flame retardants. Silver bromide is an important component in black-and-white photography emulsions.<\/p>\n<p style=\"text-align: justify;\">Iodine is used in tinctures, pharmaceuticals, and disinfectants. The radioactive isotope <sup>131<\/sup>I is applied in nuclear medicine as a tracer for diagnosing thyroid disorders.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Halogens_in_Everyday_Life\"><\/span>Halogens in Everyday Life<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"text-align: justify;\">Halogen compounds are encountered in many aspects of daily life. Most people season their food with sodium chloride, also known as table salt. This may contain sodium or potassium iodate to prevent iodine deficiency. For dental health, sodium or potassium fluoride may be added.<\/p>\n<p style=\"text-align: justify;\">Chlorine-based cleaning agents used for disinfecting kitchens and sanitary facilities contain chlorides and hypochlorites.<\/p>\n<p style=\"text-align: justify;\">Fluorinated compounds are found in non-stick coatings for pans and in outdoor textile finishes. They are also present in waterproofing sprays. For many DIY enthusiasts, <a href=\"https:\/\/www.rct-online.de\/en\/semi-finished-products\/adhesive-tapes-and-tapes\/adhesive-tapes-and-tapes-made-of-elastomers-or-plastics\/30077\/high-tech-ptfe-sealing-tape\">PTFE sealing tape<\/a> is an essential sealing material when replacing water pipes or taps. However, some per- and <a href=\"https:\/\/www.rct-online.de\/magazin\/en\/pfas-ban-will-all-fluoropolymers-be-prohibited\/\">polyfluoroalkyl substances (PFAS)<\/a> have come under scrutiny due to health and environmental concerns.<\/p>\n<p><a href=\"https:\/\/www.rct-online.de\/en\/semi-finished-products\/adhesive-tapes-and-tapes\/adhesive-tapes-and-tapes-made-of-elastomers-or-plastics\/30077\/high-tech-ptfe-sealing-tape\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-10293 size-medium\" title=\"High-Tech PTFE Sealing Tape\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-abdichtband-300x300.jpg\" alt=\"High-Tech PTFE Sealing Tape\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-abdichtband-300x300.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-abdichtband-150x150.jpg 150w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/ptfe-abdichtband.jpg 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a> <a href=\"https:\/\/www.rct-online.de\/en\/tube-hose-connectors\/connectors-made-of-plastic\/screw-joints-for-rigid-tubes-and-pipes\/31319\/straight-pipe-connector-made-of-pa-or-pvdf\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-10294 size-medium\" title=\"Straight Pipe Connector made of PA or PVDF\" src=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/gerader-rohrverbinder-aus-pa-oder-pvdf-300x300.jpg\" alt=\"Straight Pipe Connector made of PA or PVDF\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/gerader-rohrverbinder-aus-pa-oder-pvdf-300x300.jpg 300w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/gerader-rohrverbinder-aus-pa-oder-pvdf-150x150.jpg 150w, https:\/\/www.rct-online.de\/magazin\/wp-content\/uploads\/2025\/08\/gerader-rohrverbinder-aus-pa-oder-pvdf.jpg 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p style=\"text-align: justify;\">Iodine and bromine are present in small quantities in halogen lamps and headlights. Iodine compounds, important sources of iodine for the thyroid gland, are found in foods such as fish, milk, and eggs. Even if often unnoticed, halogens are indispensable elements for our health and everyday life.<\/p>\n<pre><strong>Image Sources:<\/strong>\r\nHeader image | \u00a9 Kim - stock.adobe.com\r\nPeriodic table: \u00a9 kolonko stock.adobe.com\r\nColoration of the four stable halogens: \u00a9 Tomihahndorf, CC BY-SA 3.0 &lt;http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/&gt;, via Wikimedia Commons\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>When hearing the term \u201chalogen,\u201d many people first think of lamps or headlights. However, halogens are found in numerous products we use every day. This article explains what halogens are and where they are applied. What Are Halogens? The name \u201chalogen\u201d is derived from the Greek words \u201chals\u201d (salt) and \u201cgennan\u201d (to produce), reflecting their &hellip;<\/p>\n","protected":false},"author":13,"featured_media":13601,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,2748],"tags":[3953],"class_list":["post-16100","post","type-post","status-publish","format-standard","has-post-thumbnail","","category-all-articles","category-materials-in-chemistry","tag-halogens"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v23.1 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Uses and Properties of the Halogens \u2013 What Fluorine, Chlorine &amp; Co. 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