{"id":746,"date":"2012-06-02T17:10:07","date_gmt":"2012-06-02T21:10:07","guid":{"rendered":"http:\/\/www.chemicool.com\/elements\/?page_id=746"},"modified":"2017-12-07T02:08:24","modified_gmt":"2017-12-07T07:08:24","slug":"protactinium","status":"publish","type":"page","link":"https:\/\/www.chemicool.com\/elements\/protactinium.html","title":{"rendered":"Protactinium 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=\"rareT\">\n<div class=\"atnorT\">91<\/div>\n<div class=\"clearT\"><\/div>\n<div class=\"elnamT\">Pa<\/div>\n<div class=\"atweiT\">(231.0)<\/div>\n<\/div>\n<p>The chemical element protactinium is classed as an actinide metal. It was discovered in 1913 by Kasimir Fajans and Oswald G&#246;hring.<\/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>  Protactinium is an actinide metal  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Color:<\/td>\n<td>  silvery  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Atomic weight:<\/td>\n<td>  231.0359, no stable isotopes <\/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>  1570 <sup>o<\/sup>C, 1843 K    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Boiling point:<\/td>\n<td>  4000 <sup>o<\/sup>C, 4273 K    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electrons:<\/td>\n<td>91<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Protons:<\/td>\n<td>91<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Neutrons in most abundant isotope:<\/td>\n<td>140<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron shells:<\/td>\n<td>   2,8,18,32,20,9,2   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron configuration:<\/td>\n<td>   [Rn] 5f<sup>2<\/sup> 6d<sup>1<\/sup> 7s<sup>2<\/sup>    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Density @ 20<sup>o<\/sup>C:<\/td>\n<td>  15.4 g\/cm<sup>3<\/sup>  <\/td>\n<\/tr>\n<\/table>\n<span class=\"collapseomatic \" id=\"id6a4221a4e37f2\"  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-id6a4221a4e37f2\" class=\"collapseomatic_content \">\n<table class=\"datatop\">\n<tr>\n<td class=\"elemglb\">Atomic volume:<\/td>\n<td>   15.0  cm<sup>3<\/sup>\/mol   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Structure:<\/td>\n<td>   fcc: face-centered cubic <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Hardness: <\/td>\n<td>  &#8211;   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Specific heat capacity<\/td>\n<td>   0.12 J g<sup>-1<\/sup> K<sup>-1<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of fusion<\/td>\n<td> 12.34 kJ mol<sup>-1<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of atomization<\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of vaporization<\/td>\n<td>   481 kJ mol<sup>-1<\/sup>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">1<sup>st<\/sup> ionization energy<\/td>\n<td>  568 kJ mol<sup>-1<\/sup>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">2<sup>nd<\/sup> ionization energy<\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">3<sup>rd<\/sup> ionization energy<\/td>\n<td>   &#8211;   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron affinity<\/td>\n<td>  &#8211;  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Minimum oxidation number<\/td>\n<td>  0    <\/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> 5 <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Max. common oxidation no. <\/td>\n<td>  5  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Electronegativity (Pauling Scale) <\/td>\n<td> 1.5    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Polarizability volume <\/td>\n<td>    25.4 &Aring;<sup>3<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with air<\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 15 M HNO<sub>3<\/sub> <\/td>\n<td>  &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 6 M HCl <\/td>\n<td> &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 6 M NaOH <\/td>\n<td>   none  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Oxide(s) <\/td>\n<td>  PaO PaO<sub>2<\/sub> Pa<sub>2<\/sub>O<sub>5<\/sub>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Hydride(s) <\/td>\n<td>   PaH<sub>3<\/sub>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Chloride(s) <\/td>\n<td>  PaCl<sub>4<\/sub> PaCl<sub>5<\/sub>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Atomic radius <\/td>\n<td>  163 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>  118 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\"> Thermal conductivity <\/td>\n<td> 47  W m<sup>-1<\/sup> K<sup>-1<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Electrical conductivity <\/td>\n<td>   5.6 x 10<sup>6<\/sup> S m<sup>-1<\/sup>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Freezing\/Melting point:<\/td>\n<td>  1570 <sup>o<\/sup>C, 1843 K    <\/td>\n<\/tr>\n<\/table>\n<\/div>\n<\/div>\n<div class=\"leftimagepadding\">\n<div style=\"width: 310px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/chemicool.com\/elements\/images\/300-meitner-hahn.jpg\" width=\"300\" height=\"159\" alt=\"Lise Meitner and Otto Hahn\" class=\"size-full\" \/><p class=\"wp-caption-text\">Lise Meitner and Otto Hahn in the laboratory.<\/p><\/div>\n<\/div>\n<\/div>\n<p><a id=\"discovery\"><\/a><\/p>\n<h2>Discovery of Protactinium<\/h2>\n<div class=\"author\">Dr. Doug Stewart<\/div>\n<p>    The discovery story of protactinium spans several years. Polish chemist Kasimir Fajans and German chemist Oswald G&#246;hring discovered protactinium in 1913 at Karlsruhe, Germany. They called the element &#8216;brevium&#8217; because the isotope they had found (protactinium-234) has a very short half-life (1.17 minutes). <sup>(1),(2)<\/sup><\/p>\n<p>\t\t Otto Hahn and Lise Meitner at the Kaiser Wilhelm Institute in Berlin, discovered a much longer lived isotope in 1917: protactinium-231 (half-life of 32&#8201;670 years). Hahn and Meitner were searching for a &#8216;mother substance&#8217; that decayed to actinium.<\/p>\n<p>\t\t Otto Hahn wrote that their goal was &#8220;to find that substance which&#8230; forms the starting point for the actinium series, and to determine whether and through which intermediates actinium is derived.&#8221; <sup>(1)<\/sup><\/p>\n<p>\t\tTheir work was interrupted by the First World War. In 1917 they examined silica residue they had extracted from pitchblende (uranium oxide) over two years earlier. <\/p>\n<p>They identified protactinium-231 by establishing that no known substance could have emitted the alpha particles that were observed and by the actinium produced.<\/p>\n<p>Frederic Soddy and John Cranston also discovered protactinium independently in 1917, at the University of Glasgow, Scotland. <sup>(1),(3)<\/sup><\/p>\n<p>In 1927 Aristid von Grosse isolated protactinium oxide (Pa<sub>2<\/sub>O<sub>5<\/sub>). In 1934 he isolated the element from the oxide by converting it to the iodide (PaI<sub>5<\/sub>) and then decomposed it using a heated filament in a high vacuum. <sup>(4)<\/sup><\/p>\n<p>The element name comes from a combination of the Greek word &#8216;protos&#8217; meaning first and &#8216;actinium.&#8217;\t\t\t\t<\/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=\"225\" src=\"https:\/\/www.youtube.com\/embed\/G1PZL1kjk5g?rel=0\" allowfullscreen><\/iframe><\/p>\n<div class=\"youtubecaption\">An investigation into the decay of protactinium.<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p><a id=\"appear\"><\/a><\/p>\n<h3>Appearance and Characteristics<\/h3>\n<p>  <strong>Harmful effects:<\/strong> <\/p>\n<p>\t \tProtactinium is harmful due to its radioactivity and is also toxic. <\/p>\n<p>\t  <strong>Characteristics:<\/strong><\/p>\n<p>\t\t Protactinium is a very rare shiny, silvery, highly radioactive metal that tarnishes slowly in air to the oxide.<\/p>\n<p>Almost all naturally occurring protactinium is the 231 isotope. It emits alpha radiation and is produced through the decay of <a href=\"https:\/\/www.chemicool.com\/elements\/uranium.html\">uranium-235<\/a>.<\/p>\n<p>Protactinium is one of the rarest and most expensive naturally occurring elements.<\/p>\n<p>The largest amount of protactinium obtained so far has been 125 grams in 1961 from the Great Britain Atomic Energy Authority. The extraction was made from 60 tons of nuclear waste material. <sup>(5)<\/sup><\/p>\n<p><a id=\"uses\"><\/a><\/p>\n<h2>Uses of Protactinium<\/h2>\n<p>\t\tProtactinium is used mainly for research purposes.<\/p>\n<p>\t\tProtactinium-231 combined with the <a href=\"https:\/\/www.chemicool.com\/elements\/thorium.html\">thorium-230<\/a> can be used to date marine sediments. <sup>(6)<\/sup><\/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>  0.1 part per trillion , 0.001 by moles<\/p>\n<p>\t\t<span class=\"elemgl\">Abundance solar system:<\/span> negligible<\/p>\n<p>\t\t\t\t<span class=\"elemgl\">Cost, pure:<\/span>  $280 per g<\/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> Protactinium occurs naturally in minute amounts (up to 3 parts per million) in uranium ores. Protactinium can also obtained as a by-product of uranium processing.<\/p>\n<p>\t\t<span class=\"elemgl\">Isotopes:<\/span> Protactinium has 27 isotopes whose half-lives are known, with mass numbers 212 to 238. Protactinium has no stable isotopes. Its longest lived isotopes are <sup>231<\/sup>Pa, with a half-life of 32,760 years, <sup>233<\/sup>Pa with a half-life of 26.967 days and <sup>230<\/sup>Pa with a half-life of 17.4 days.<\/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<ol>\n<li>Ruth Lewin Sime, The Discovery of Protactinium., Journal of Chemical Education., 63.8 August 1986 pages 653 &#8211; 657.<\/li>\n<li> Jeremy Bernstein, Plutonium: A History of the World&#8217;s Most Dangerous Element., National Academies Press, 2007 page 40.<\/li>\n<li><a href=\"http:\/\/worldchanging.gla.ac.uk\/article\/?id=37\">Discovery of Protactinium, University of Glasgow<\/a><\/li>\n<li>John Emsley, Nature&#8217;s building blocks: an A-Z guide to the elements., Oxford University Press, 2003 page 348.<\/li>\n<li> Andrew Ede, The chemical element: a historical perspective., Greenwood Publishing Group, 2006 page 146.<\/li>\n<li>John P Rafferty, Geochronology, Dating, and Precambrian Time: The Beginning of the World as We Know It., The Rosen Publishing Group, 2010 page 152.<\/li>\n<\/ol>\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\/protactinium.html\"&gt;Protactinium&lt;\/a&gt;\r\n<\/pre>\n<p>or<\/p>\n<pre class='code'>\r\n&lt;a href=\"https:\/\/www.chemicool.com\/elements\/protactinium.html\"&gt;Protactinium 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\"Protactinium.\" Chemicool Periodic Table. Chemicool.com. 28 Feb. 2015. 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\/protactinium.html&gt;.<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Data Zone | Discovery | Facts | Appearance &amp; Characteristics | Uses | Abundance &amp; Isotopes | References 91 Pa (231.0) The chemical element protactinium is classed as an actinide metal. It was discovered in 1913 by Kasimir Fajans and Oswald G&#246;hring. Data Zone Classification: Protactinium is an actinide metal Color: silvery Atomic weight: 231.0359, [&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-746","1":"page","2":"type-page","3":"status-publish","5":"entry"},"_links":{"self":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/746","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=746"}],"version-history":[{"count":26,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/746\/revisions"}],"predecessor-version":[{"id":4288,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/746\/revisions\/4288"}],"wp:attachment":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/media?parent=746"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}