{"id":777,"date":"2012-06-03T09:45:31","date_gmt":"2012-06-03T09:45:31","guid":{"rendered":"http:\/\/www.chemicool.com\/elements\/?page_id=777"},"modified":"2017-12-07T02:07:25","modified_gmt":"2017-12-07T07:07:25","slug":"californium","status":"publish","type":"page","link":"https:\/\/www.chemicool.com\/elements\/californium.html","title":{"rendered":"Californium 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\">98<\/div>\n<div class=\"clearT\"><\/div>\n<div class=\"elnamT\">Cf<\/div>\n<div class=\"atweiT\">(251)<\/div>\n<\/div>\n<p>The chemical element californium is classed as an actinide metal. It was discovered in 1950 by Stanley Thompson, Kenneth Street, Albert Ghiorso and Glenn Seaborg.<\/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>  Californium is an actinide metal  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Color:<\/td>\n<td>  silvery-white <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Atomic weight:<\/td>\n<td> (251), 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> 900 <sup>o<\/sup>C, 1173 K    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Boiling point:<\/td>\n<td>   1472 <sup>o<\/sup>C, 1745 K (estimated)    <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electrons:<\/td>\n<td>98<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Protons:<\/td>\n<td>98<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Neutrons in most abundant isotope:<\/td>\n<td>153<\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron shells:<\/td>\n<td>   2,8,18,32,28,8,2   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Electron configuration:<\/td>\n<td>   [Rn] 5f<sup>10<\/sup> 7s<sup>2<\/sup>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Density @ 20<sup>o<\/sup>C:<\/td>\n<td>  13.67 g\/cm<sup>3<\/sup>  <\/td>\n<\/tr>\n<\/table>\n<span class=\"collapseomatic \" id=\"id69e353c123f4d\"  tabindex=\"0\" title=\"Show more, including: Heats, Energies, Oxidation, Reactions,&lt;br \/&gt; Compounds, Radii, Conductivities\"    >Show more, including: Heats, Energies, Oxidation, Reactions,<br \/> Compounds, Radii, Conductivities<\/span><div id=\"target-id69e353c123f4d\" class=\"collapseomatic_content \">\n<table class=\"datatop\">\n<tr>\n<td class=\"elemglb\">Atomic volume:<\/td>\n<td>   18.4 cm<sup>3<\/sup>\/mol   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Structure:<\/td>\n<td>   double hexagonal close-packed <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Hardness: <\/td>\n<td>      <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Specific heat capacity<\/td>\n<td> &#8211;  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Heat of fusion<\/td>\n<td>  &#8211; <\/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>  &#8211;  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">1<sup>st<\/sup> ionization energy<\/td>\n<td>  608 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> 4 <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Max. common oxidation no. <\/td>\n<td>  3  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Electronegativity (Pauling Scale) <\/td>\n<td> 1.3   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Polarizability volume <\/td>\n<td>   20.5 &Aring;<sup>3<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with air<\/td>\n<td>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 15 M HNO<sub>3<\/sub> <\/td>\n<td>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 6 M HCl <\/td>\n<td>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Reaction with 6 M NaOH <\/td>\n<td>   <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Oxide(s) <\/td>\n<td>   CfO, Cf<sub>2<\/sub>O<sub>3<\/sub>, CfO<sub>2<\/sub> , Cf<sub>7<\/sub>O<sub>12<\/sub> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Hydride(s) <\/td>\n<td>   &#8211;  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Chloride(s) <\/td>\n<td>  CfCl<sub>3<\/sub>  <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Atomic radius <\/td>\n<td>      186 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>   109 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> 10 W m<sup>-1<\/sup> K<sup>-1<\/sup> <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\"> Electrical conductivity <\/td>\n<td>  &#8211; <\/td>\n<\/tr>\n<tr>\n<td class=\"elemglb\">Freezing\/Melting point:<\/td>\n<td> 900 <sup>o<\/sup>C, 1173 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-supernova-cas-a.jpg\" width=\"300\" height=\"158\" alt=\"The spectrum of californium-254\" class=\"size-full\" \/><p class=\"wp-caption-text\">The spectrum of californium-254 has been recorded in supernovae. Image by NASA\/CXC\/MIT\/UMass Amherst\/M.D. Stage et al.<\/p><\/div>\n<\/div>\n<\/div>\n<p><a id=\"discovery\"><\/a><\/p>\n<h2>Discovery of Californium<\/h2>\n<div class=\"author\">Dr. Doug Stewart<\/div>\n<p>   Californium was the sixth synthetic transuranium element of the actinide series to be discovered.<\/p>\n<p>It was first produced by Stanley Thompson, Kenneth Street, Albert Ghiorso and Glenn Seaborg in 1950 in California, USA.<\/p>\n<p>The researchers bombarded <a href=\"https:\/\/www.chemicool.com\/elements\/curium.html\">curium-242<\/a> with alpha particles in the 60-inch cyclotron in Berkeley, California. Each nuclear reaction created californium-245 (half-life 44 minutes) and a neutron. Only about 700,000 atoms of californium-245 were produced in the experiment. This number of atoms is enough to make a cube with sides about 27 nanometers long. Chemical analysis proved that the new element had been made. <sup>(1)<\/sup><\/p>\n<p>Californium was isolated in macro quantities for the first time by Burris Cunningham and Stanley Thompson in 1958 at the Materials Testing Reactor in Arco, Idaho by prolonged (five years) neutron irradiation of <a href=\"plutonium.html\">plutonium-239<\/a>. Approximately 1.2 micrograms of californium and 0.6 micrograms of <a href=\"berkelium.html\">berkelium<\/a> were synthesized. <sup>(1a)<\/sup><\/p>\n<p>The element was named after the U.S. State of California and the University of California.<\/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<div style=\"width: 310px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.chemicool.com\/elements\/images\/300-californium-mine-detector.jpg\" width=\"300\" height=\"365\" alt=\"Timed Neutron Detector\" class=\"size-full\" \/><p class=\"wp-caption-text\">An engineer tests the prototype Timed Neutron Detector, a device that detects landmines. The neutron source of the landmine detector holds a tiny amount of californium-252. (Photo credit: Pacific Northwest National Lab)<\/p><\/div>\n<p><iframe loading=\"lazy\" width=\"300\" height=\"225\" src=\"https:\/\/www.youtube.com\/embed\/LxFXX0-hUYQ?rel=0\" allowfullscreen><\/iframe><\/p>\n<div class=\"youtubecaption\">Transuranium elements discovery and experiments. 1963 chemistry educational documentary narrated by Glenn Seaborg, Stanley Thompson and Albert Ghiorso.<\/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>\tCalifornium is harmful due to its radioactivity. <\/p>\n<p>\t  <strong>Characteristics:<\/strong><\/p>\n<p>\t\t Californium is a synthetic radioactive silvery-white metal of moderate chemical reactivity. <\/p>\n<p>\t\tIt is a relatively soft, malleable  metal and is easily cut with a razor-blade.<\/p>\n<p>\t\tIt slowly tarnishes in air to the oxide at room temperature. <sup>(2)<\/sup><\/p>\n<p>\t\tCalifornium-252 is a very strong neutron emitter.<\/p>\n<p><a id=\"uses\"><\/a><\/p>\n<h2>Uses of Californium<\/h2>\n<p>\t\tCalifornium-252 (half-life of 2.645 years) is produced in nuclear reactors and has found a variety of uses.<\/p>\n<p>\t\tIt is used as a neutron emitter, providing neutrons for the start-up of nuclear reactors.<\/p>\n<p>\t\tIt has also been used as a target material for producing transcalifornium elements. <a href=\"ununoctium.html\">Ununoctium<\/a>, the heaviest of the elements, was produced when a <a href=\"californium.html\">californium<\/a> target was bombarded with <a href=\"calcium.html\">calcium<\/a> ions. <sup>(2a)<\/sup><\/p>\n<p>\t\tCalifornium-252 is used in to treat cervical cancer. It is also used to analyze the sulfur content of petroleum and in neutron moisture gauges to measure the moisture content of soil. <sup>(3)<\/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>  nil<\/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>  $ 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> Californium is a synthetic element and is not found naturally on Earth. The spectrum of californium-254 has been observed in supernovae. <sup>(4)<\/sup> Californium is produced in nuclear reactors by bombarding plutonium with neutrons and in particle accelerators.<\/p>\n<p>\t\t<span class=\"elemgl\">Isotopes:<\/span> Californium has 20 isotopes whose half-lives are known, with mass numbers 237 to 256. Californium has no naturally occurring isotopes. Its longest lived isotopes are <sup>251<\/sup>Cf, with a half-life of 898 years, <sup>249<\/sup>Cf with a half-life of 351 years and <sup>250<\/sup>Cf with a half-life of 13.08 years.<\/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>B. B. Cunningham, Berkelium and Californium., Journal of Chemical Education, Vol 36.1 (1959) p32-33. 1a. p35. <\/li>\n<li>Richard G. Haire, The Chemistry of the Actinide and Transactinide Elements., Springer., Vol 3.12., p1526-1527. 2a. p1503 &#8211; 1507. <\/li>\n<li><a href=\"http:\/\/www.ig.energy.gov\/documents\/OAS-FS-11-06.pdf\">United States Department of Energy<\/a>., page 69 (pdf).<\/li>\n<li>W. Baade, G. Burbidge, F. Hoyle, E. Burbidge, R. Christy, W. Fowler, Supernovae and Californium 254., Publications of the Astronomical Society of the Pacific, Vol 68.403 p.296- 297.   <\/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\/californium.html\"&gt;Californium&lt;\/a&gt;\r\n<\/pre>\n<p>or<\/p>\n<pre class='code'>\r\n&lt;a href=\"https:\/\/www.chemicool.com\/elements\/californium.html\"&gt;Californium 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\"Californium.\" Chemicool Periodic Table. Chemicool.com. 16 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\/californium.html&gt;.<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Data Zone | Discovery | Facts | Appearance &amp; Characteristics | Uses | Abundance &amp; Isotopes | References 98 Cf (251) The chemical element californium is classed as an actinide metal. It was discovered in 1950 by Stanley Thompson, Kenneth Street, Albert Ghiorso and Glenn Seaborg. Data Zone Classification: Californium is an actinide metal Color: [&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-777","1":"page","2":"type-page","3":"status-publish","5":"entry"},"_links":{"self":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/777","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=777"}],"version-history":[{"count":19,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/777\/revisions"}],"predecessor-version":[{"id":4213,"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/pages\/777\/revisions\/4213"}],"wp:attachment":[{"href":"https:\/\/www.chemicool.com\/elements\/wp-json\/wp\/v2\/media?parent=777"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}