{"id":420,"date":"2012-05-25T13:09:40","date_gmt":"2012-05-25T13:09:40","guid":{"rendered":"http:\/\/www.chemicool.com\/elements\/?page_id=420"},"modified":"2017-12-07T02:08:08","modified_gmt":"2017-12-07T07:08:08","slug":"iodine","status":"publish","type":"page","link":"https:\/\/www.chemicool.com\/elements\/iodine.html","title":{"rendered":"Iodine Element Facts"},"content":{"rendered":"<div class=\"insidepagelinks\">\n<a href=\"#data\">Data Zone<\/a> |  <a href=\"#discovery\">Discovery<\/a> |  <a href=\"#facts\">Facts<\/a> | <a href=\"#appear\">Appearance &amp; Characteristics<\/a> | <a href=\"#uses\">Uses<\/a> | <a href=\"#abund\">Abundance &amp; Isotopes<\/a>  | <a href=\"#refer\">References<\/a>\n<\/div>\n<div class=\"halogensT\">\n<div class=\"atnorT\">53<\/div>\n<div class=\"clearT\"><\/div>\n<div class=\"elnamT\">I<\/div>\n<div class=\"atweiT\"> 126.9<\/div>\n<\/div>\n<p>The chemical element iodine is classed as a halogen and a nonmetal. It was discovered in 1811 by Bernard Courtois.<\/p>\n<div style=\"clear:both;\"><\/div>\n<div class=\"adsense300\">\n<div class=\"adsense300spacer\">\n<div style=\"line-height:10px;\"><img decoding=\"async\" src=\"\/\/www.chemicool.com\/ad.png\" alt=\"\" \/><\/div>\n<p><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script><ins class=\"adsbygoogle\" style=\"display: block;\" data-ad-client=\"ca-pub-9461632227417539\" data-ad-slot=\"8753977201\" data-ad-format=\"auto\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/p>\n<p><a id=\"data\"><\/a><\/p>\n<h2>Data Zone<\/h2>\n<table class=\"datatop\">\n<tr>\n<td class=\"elemglb\">Classification:<\/td>\n<td>  Iodine is a halogen and a nonmetal   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Color:<\/td>\n<td>  bluish-black solid, purple vapor <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Atomic weight:<\/td>\n<td>   126.9045 <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">State:<\/td>\n<td>   solid  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Melting point:<\/td>\n<td> 113.5 <sup>o<\/sup>C, 386.6 K     <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Boiling point:<\/td>\n<td>  184 <sup>o<\/sup>C, 457 K    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electrons:<\/td>\n<td>53<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Protons:<\/td>\n<td>53<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Neutrons in most abundant isotope:<\/td>\n<td>74<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron shells:<\/td>\n<td>   2,8,18,18,7   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron configuration:<\/td>\n<td>   [Kr] 4d<sup>10<\/sup> 5s<sup>2<\/sup> 5p<sup>5<\/sup>    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Density @ 20<sup>o<\/sup>C:<\/td>\n<td>  4.93 g\/cm<sup>3<\/sup>   <\/td>\n<\/tr>\n<\/table>\n<span class=\"collapseomatic \" id=\"id6a6410ca60cb5\"  tabindex=\"0\" title=\"Show more, including: Heats, Energies, Oxidation,&lt;br \/&gt; Reactions, Compounds, Radii, Conductivities\"    >Show more, including: Heats, Energies, Oxidation,<br \/> Reactions, Compounds, Radii, Conductivities<\/span><div id=\"target-id6a6410ca60cb5\" class=\"collapseomatic_content \">\n<table class=\"datatop\">\n<tr>\n<td class=\"elemglb\">Atomic volume:<\/td>\n<td>   25.74 cm<sup>3<\/sup>\/mol   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Structure:<\/td>\n<td>   layers of I<sub>2<\/sub> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Specific heat capacity<\/td>\n<td>  0.214 J g<sup>-1<\/sup> K<sup>-1<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of fusion<\/td>\n<td> 15.52 kJ mol<sup>-1<\/sup> of I<sub>2<\/sub> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of atomization<\/td>\n<td>  107 kJ mol<sup>-1<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of vaporization<\/td>\n<td>   41.57 kJ mol<sup>-1<\/sup> of I<sub>2<\/sub>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">1<sup>st<\/sup> ionization energy<\/td>\n<td>  1008.4 kJ mol<sup>-1<\/sup>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">2<sup>nd<\/sup> ionization energy<\/td>\n<td>  1845.8 kJ mol<sup>-1<\/sup>    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">3<sup>rd<\/sup> ionization energy<\/td>\n<td>  3184 kJ mol<sup>-1<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron affinity<\/td>\n<td>    295.16 kJ mol<sup>-1<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Minimum oxidation number<\/td>\n<td>  -1    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Min. common oxidation no.<\/td>\n<td>  0   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Maximum oxidation number <\/td>\n<td> 7 <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Max. common oxidation no. <\/td>\n<td> 7  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Electronegativity (Pauling Scale) <\/td>\n<td> 2.66  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Polarizability volume <\/td>\n<td>   5 &Aring;<sup>3<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with air<\/td>\n<td> none  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 15 M HNO<sub>3<\/sub> <\/td>\n<td>   mild, &#8658; HIO<sub>3<\/sub>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 6 M HCl <\/td>\n<td>  none <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 6 M NaOH <\/td>\n<td>    mild, &#8658; OI<sup>&#8211;<\/sup>, I<sup>&#8211;<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Oxide(s) <\/td>\n<td>  I<sub>2<\/sub>O<sub>5<\/sub>, I<sub>4<\/sub>O<sub>9<\/sub>, I<sub>2<\/sub>O<sub>4<\/sub> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Hydride(s) <\/td>\n<td>    HI   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Chloride(s) <\/td>\n<td>  ICl, ICl<sub>3<\/sub>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Atomic radius <\/td>\n<td>  140 pm <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Ionic radius (1+ ion) <\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Ionic radius (2+ ion) <\/td>\n<td>   &#8211;  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Ionic radius (3+ ion) <\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Ionic radius (1- ion) <\/td>\n<td>    206 pm  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Ionic radius (2- ion) <\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Ionic radius (3- ion) <\/td>\n<td>   &#8211;  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Thermal conductivity <\/td>\n<td>  0.45 W m<sup>-1<\/sup> K<sup>-1<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Electrical conductivity <\/td>\n<td>  1.0 x 10<sup>-5<\/sup> S m<sup>-1<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Freezing\/Melting point:<\/td>\n<td> 113.5 <sup>o<\/sup>C, 386.6 K     <\/td>\n<\/tr>\n<\/table>\n<\/div>\n<\/div>\n<div class=\"leftimagepadding\">\n<\/div>\n<\/div>\n<p><a id=\"discovery\"><\/a><\/p>\n<h2>Discovery of Iodine<\/h2>\n<div class=\"author\">Dr. Doug Stewart<\/div>\n<p>Iodine was discovered by Bernard Courtois in 1811 in France.<\/p>\n<p>Courtois was trying to extract potassium chloride from seaweed. After crystallizing the potassium chloride, he added sulfuric acid to the remaining liquid. <\/p>\n<p>This, rather surprisingly, produced a purple vapor, which condensed into dark crystals. These were the first crystals of iodine ever made.<\/p>\n<p>Courtois studied this new substance and found that it combined well with phosphorous and hydrogen, but it did not form compounds easily with carbon or oxygen.<\/p>\n<p>He also discovered that when mixed with ammonia it formed a brown colored solid (nitrogen triiodide) that exploded at the slightest touch.  <\/p>\n<p>Iodine&#8217;s name comes from the Greek work &#8216;iodes&#8217; meaning violet. Iodine&#8217;s purple vapor is shown below in a photo by Matias Molnar.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/chemicool.com\/elements\/images\/300-iodine-vapor.jpg\" width=\"300\" height=\"208\" alt=\"Iodine Vapor\" class=\"aligncenter size-full\" \/><\/p>\n<div style=\"clear:both;line-height:20px;\">&nbsp;<\/div>\n<div class=\"adsense300\">\n<div class=\"adsense300spacer\">\n<div style=\"line-height: 10px;\"><img decoding=\"async\" src=\"\/\/www.chemicool.com\/ad.png\" alt=\"\" \/><\/div>\n<p><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script><ins class=\"adsbygoogle\" style=\"display: inline-block; width: 336px; height: 280px;\" data-ad-client=\"ca-pub-9461632227417539\" data-ad-slot=\"2986645201\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/p>\n<div class=\"leftimagepadding\">\n<p><iframe loading=\"lazy\" width=\"300\" height=\"168\" src=\"https:\/\/www.youtube.com\/embed\/BqeWpywDuiY?rel=0\" allowfullscreen><\/iframe><\/p>\n<div class=\"youtubecaption\">Chemical clock reactions &#8211; amazing color changes.<\/div>\n<p><iframe loading=\"lazy\" width=\"300\" height=\"225\" src=\"https:\/\/www.youtube.com\/embed\/E-fs9OwE9Y0?rel=0\" allowfullscreen><\/iframe><\/p>\n<div class=\"youtubecaption\">Iodine crystals sublimate (turn from solid to gas without becoming liquid) and then freeze back to solid iodine.<\/div>\n<div style=\"width: 310px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.chemicool.com\/elements\/images\/300-iodine-xtals.jpg\" width=\"300\" height=\"158\" alt=\"Iodine Crystals.\" class=\"size-full\" \/><p class=\"wp-caption-text\">Iodine Crystals. Photo by Ben Mills.<\/p><\/div>\n<\/div>\n<\/div>\n<\/div>\n<p><a id=\"appear\"><\/a><\/p>\n<h3>Appearance and Characteristics<\/h3>\n<p>\t  <strong>Harmful effects:<\/strong> <\/p>\n<p>\t \tIn small doses, iodine is slightly toxic and it is highly poisonous in large amounts. Elemental iodine is an irritant which can cause sores on the skin. Iodine vapor causes extreme eye irritation.<\/p>\n<p>\t  <strong>Characteristics:<\/strong><\/p>\n<p>\t\t Iodine is a bluish-black, lustrous solid. Although it is less reactive than the elements above it in group 17 (fluorine, chlorine and bromine) it still forms compounds with many other elements. <\/p>\n<p>\t\tAlthough iodine is a non-metal, it displays some metallic properties. <\/p>\n<p>\t\tWhen dissolved in chloroform, carbon tetrachloride or carbon disulfide, iodine yields purple colored solutions. It is barely soluble in water, giving a yellow solution. <\/p>\n<p><a id=\"uses\"><\/a><\/p>\n<h2>Uses of Iodine<\/h2>\n<p>\t\tIodine is important in medicine, in both radioactive and non-radioactive forms. Iodide and thyroxin, which contains iodine, are used inside the body. <\/p>\n<p>\t\tA solution containing potassium iodide (KI) and iodine in alcohol is used to disinfect external wounds. Elemental iodine is also used as a disinfectant. <\/p>\n<p>\t\tSilver iodide is used in photography. <\/p>\n<p>\t\tIodine is sometimes added to table salt to prevent thyroid disease. <\/p>\n<p>\t\tIodine&#8217;s other uses include catalysts, animal feeds and printing inks and dyes. <\/p>\n<p><a id=\"abund\"><\/a><\/p>\n<h2>Abundance and Isotopes<\/h2>\n<p><span class=\"elemgl\">Abundance earth&#8217;s crust:<\/span>  450 parts per billion by weight, 73 parts per billion by moles<\/p>\n<p>\t\t<span class=\"elemgl\">Abundance solar system:<\/span> parts per billion by weight, parts per billion by moles<\/p>\n<p>\t\t\t\t<span class=\"elemgl\">Cost, pure:<\/span>  $8.3 per 100g<\/p>\n<p>\t\t\t\t<span class=\"elemgl\">Cost, bulk:<\/span>   $ per 100g<\/p>\n<p>\t\t<span class=\"elemgl\">Source:<\/span> In nature, iodine occurs in the form of iodide ions, mainly in seawater. It is introduced into the food chain via seaweed and other sea-plants. Iodine is found in some minerals and soils. <\/p>\n<p>\t\tCommercially, iodine is obtained in several ways, such as taking iodine vapor from processed brine, by ion exchange of brine or by releasing iodine from iodate taken from nitrate ores. <\/p>\n<p><span class=\"elemgl\">Isotopes:<\/span> 34 whose half-lives are known, with mass numbers 108 to 141. Naturally occurring iodine consists of the one stable isotope: <sup>127<\/sup>I<\/p>\n<div style=\"max-width: 750px;\">\n<div style=\"line-height: 10px;\"><img decoding=\"async\" src=\"\/\/www.chemicool.com\/ad.png\" alt=\"\" \/><\/div>\n<p><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script><ins class=\"adsbygoogle\" style=\"display: block;\" data-ad-client=\"ca-pub-9461632227417539\" data-ad-slot=\"8753977201\" data-ad-format=\"auto\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/p>\n<\/div>\n<p><a id=\"refer\"><\/a><\/p>\n<h4>References<\/h4>\n<h4>Cite this Page<\/h4>\n<p>For online linking, please copy and paste one of the following:<\/p>\n<pre class='code'>\r\n&lt;a href=\"https:\/\/www.chemicool.com\/elements\/iodine.html\"&gt;Iodine&lt;\/a&gt;\r\n<\/pre>\n<p>or<\/p>\n<pre class='code'>\r\n&lt;a href=\"https:\/\/www.chemicool.com\/elements\/iodine.html\"&gt;Iodine Element Facts&lt;\/a&gt;\r\n<\/pre>\n<p>To cite this page in an academic document, please use the following MLA compliant citation:<\/p>\n<pre class='code'>\r\n\"Iodine.\" Chemicool Periodic Table. Chemicool.com. 17 Oct. 2012. Web. <script type=\"text\/javascript\">\r\n<!--\r\nvar currentTime = new Date()\r\nvar month = currentTime.getMonth() + 1\r\nvar day = currentTime.getDate()\r\nvar year = currentTime.getFullYear()\r\ndocument.write(month + \"\/\" + day + \"\/\" + year)\r\n\/\/-->\r\n<\/script> \r\n&lt;https:\/\/www.chemicool.com\/elements\/iodine.html&gt;.<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Data Zone | Discovery | Facts | Appearance &amp; Characteristics | Uses | Abundance &amp; Isotopes | References 53 I 126.9 The chemical element iodine is classed as a halogen and a nonmetal. It was discovered in 1811 by Bernard Courtois. Data Zone Classification: Iodine is a halogen and a nonmetal Color: bluish-black solid, purple [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"class_list":{"0":"post-420","1":"page","2":"type-page","3":"status-publish","5":"entry"},"_links":{"self":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/420","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/comments?post=420"}],"version-history":[{"count":23,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/420\/revisions"}],"predecessor-version":[{"id":4250,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/420\/revisions\/4250"}],"wp:attachment":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/media?parent=420"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}