<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0370-3908</journal-id>
<journal-title><![CDATA[Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. acad. colomb. cienc. exact. fis. nat.]]></abbrev-journal-title>
<issn>0370-3908</issn>
<publisher>
<publisher-name><![CDATA[Academia Colombiana de Ciencias Exactas, Físicas y Naturales]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0370-39082019000200291</article-id>
<article-id pub-id-type="doi">10.18257/raccefyn.917</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Los lantánidos: ni tierras ni raras]]></article-title>
<article-title xml:lang="en"><![CDATA[The lanthanides: neither earths nor rare]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Echeverri L.]]></surname>
<given-names><![CDATA[Fernando]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Parra B.]]></surname>
<given-names><![CDATA[John Jairo]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de Antioquia Instituto de Química ]]></institution>
<addr-line><![CDATA[Medellín ]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2019</year>
</pub-date>
<volume>43</volume>
<numero>167</numero>
<fpage>291</fpage>
<lpage>296</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0370-39082019000200291&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0370-39082019000200291&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0370-39082019000200291&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen La tabla periódica de los elementos contiene la base fundamental del conocimiento pasado, presente y futuro de la Química. Sin embargo, aún se proponen modelos adicionales y complementarios para tratar de satisfacer todas y cada una de las propiedades físicas y químicas, en especial de aquellos elementos que actualmente no se ajustan a ella. Algunas de esas desviaciones seguramente tendrán explicaciones por aproximaciones cuánticas, obviamente desconocidas en el tiempo de la propuesta original. Específicamente, existen dos situaciones relevantes clásicas, relacionadas con las tierras raras y los actínidos, que involucran unos 30 elementos. Estos se muestran como anexos por fuera del orden previsto y, por sus características de grupos, se organizan como períodos. A pesar de los debates en torno a la reubicación de dichos elementos, que realmente no es un mero ejercicio académico, las tierras raras son valiosos materiales con múltiples aplicaciones en la vida diaria y, además, tienen un papel fundamental en el equilibrio económico y político mundial. En este artículo se presentan varios aspectos relacionados con su posición en la tabla periódica, así como las propiedades estructurales y electrónicas de sus favorables y anómalos comportamientos, sus aplicaciones y el contexto internacional por la hegemonía mundial basada en el uso de sus elementos. © 2019. Acad. Colomb. Cienc. Ex. Fis. Nat.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract The periodic table of elements contains the fundamental basis of past, present, and future knowledge of Chemistry. However, additional and complementary models are still proposed to try to satisfy the unique physical and chemical properties of those that do not conform to it. Some of these questions will surely have explanations based on quantum approaches, obviously unknown in the time of the original proposal. In the periodic table, there are two typical relevant situations related to rare lands and actinides, involving about 30 elements. These are displayed as annexes outside the intended order and having group characteristics, they are organized as periods. Despite discussions regarding the relocation of these elements, which is not an irrelevant academic exercise, rare earths are now valuable materials with multiple applications and they have a fundamental role in economic balance and global politics. This article presents several aspects related to their position in the periodic table, as well as the structural and electronic properties of their favorable and unusual behaviors, their applications, and the international context for global hegemony founded on this type of elements. © 2019. Acad. Colomb. Cienc. Ex. Fis. Nat.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Lantánidos]]></kwd>
<kwd lng="es"><![CDATA[Tierras raras]]></kwd>
<kwd lng="es"><![CDATA[Configuración]]></kwd>
<kwd lng="es"><![CDATA[Orbital f Tabla periódica]]></kwd>
<kwd lng="es"><![CDATA[Reasignación de la posición]]></kwd>
<kwd lng="es"><![CDATA[Materiales estratégicos]]></kwd>
<kwd lng="es"><![CDATA[Aplicaciones]]></kwd>
<kwd lng="es"><![CDATA[Economía y política]]></kwd>
<kwd lng="es"><![CDATA[China Vs. Estados Unidos]]></kwd>
<kwd lng="en"><![CDATA[Lanthanides]]></kwd>
<kwd lng="en"><![CDATA[Rare earths]]></kwd>
<kwd lng="en"><![CDATA[Configuration]]></kwd>
<kwd lng="en"><![CDATA[f orbital]]></kwd>
<kwd lng="en"><![CDATA[Periodic table]]></kwd>
<kwd lng="en"><![CDATA[Position reassignment]]></kwd>
<kwd lng="en"><![CDATA[Strategy material]]></kwd>
<kwd lng="en"><![CDATA[Application]]></kwd>
<kwd lng="en"><![CDATA[Economy and politics]]></kwd>
<kwd lng="en"><![CDATA[China vs USA]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="">
<collab>American Chemical Society</collab>
<source><![CDATA[Separation of rare earth elements. 1999]]></source>
<year>1999</year>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Balaram]]></surname>
<given-names><![CDATA[V]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Rare earth elements: A review of applications, occurrence, exploration, analysis, recycling, and environmental impact]]></article-title>
<source><![CDATA[Geoscience Frontiers]]></source>
<year>2018</year>
<volume>10</volume>
<page-range>1285-303</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Behrsing]]></surname>
<given-names><![CDATA[T.]]></given-names>
</name>
<name>
<surname><![CDATA[Deacon]]></surname>
<given-names><![CDATA[G.B.]]></given-names>
</name>
<name>
<surname><![CDATA[Junk]]></surname>
<given-names><![CDATA[P.C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The chemistry of rare earth metals, compounds and corrosion inhibitors]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Forsyth]]></surname>
<given-names><![CDATA[Maria]]></given-names>
</name>
<name>
<surname><![CDATA[Hinton]]></surname>
<given-names><![CDATA[Bruce]]></given-names>
</name>
</person-group>
<source><![CDATA[Rare Earth-based Corrosion Inhibitors. Woodhead Publishing Series in Metals and Surface Engineering (61)]]></source>
<year>2014</year>
<page-range>1-37</page-range><publisher-loc><![CDATA[Elsevier, Amsterdam ]]></publisher-loc>
<publisher-name><![CDATA[the Netherlands]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Binnemans]]></surname>
<given-names><![CDATA[K]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Recycling of rare earths: A critical review]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Jones]]></surname>
<given-names><![CDATA[P. T]]></given-names>
</name>
<name>
<surname><![CDATA[Blanpain]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Van Gerven]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
<name>
<surname><![CDATA[Yang]]></surname>
<given-names><![CDATA[Y]]></given-names>
</name>
<name>
<surname><![CDATA[Walton]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Buchert]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<source><![CDATA[Journal Cleaner Production]]></source>
<year>2013</year>
<volume>51</volume>
<page-range>1-22</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ganguli]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Cook]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Rare earths: A review of the landscape]]></article-title>
<source><![CDATA[MRS Energy &amp; Sustainability]]></source>
<year>2018</year>
<volume>5</volume>
</nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gschneidner]]></surname>
<given-names><![CDATA[K.A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Rare Earths and Magnetic Refrigeration]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Pecharsky]]></surname>
<given-names><![CDATA[VK]]></given-names>
</name>
</person-group>
<source><![CDATA[Journal of Rare Earths]]></source>
<year>2006</year>
<volume>24</volume>
<page-range>641-7</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hornby]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Sanderson]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
</person-group>
<source><![CDATA[Rare earths: Beijing threatens a new front in the trade war]]></source>
<year>2019</year>
<publisher-name><![CDATA[Financial Times]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="">
<collab>IUPAC</collab>
<source><![CDATA[Periodic Table of Elements]]></source>
<year>2018</year>
</nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="">
<collab>iNEMI</collab>
<source><![CDATA[White Paper: Rare Earth Metals Current Status &amp; Future Outlook. iNEMI Rare Earth Metals Project Team Second Quarter]]></source>
<year>2014</year>
</nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="">
<collab>Geological Society of London</collab>
<source><![CDATA[Rare Earth Elements]]></source>
<year>2011</year>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Law]]></surname>
<given-names><![CDATA[Y-H]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Politics could upend global trade in rare earth elements]]></article-title>
<source><![CDATA[Science]]></source>
<year>2019</year>
<volume>364</volume>
<page-range>114-5</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lemonick]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Rearranging the table]]></article-title>
<source><![CDATA[Chem Eng News]]></source>
<year>2019</year>
<volume>97</volume>
<page-range>26-9</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kirkpatrick]]></surname>
<given-names><![CDATA[K]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Electronics Need Rare Earths]]></article-title>
<source><![CDATA[Communications ACM]]></source>
<year>2019</year>
<volume>62</volume>
<page-range>17-8</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rich]]></surname>
<given-names><![CDATA[R.L.]]></given-names>
</name>
<name>
<surname><![CDATA[Laing]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Can the periodic table be improved?]]></article-title>
<source><![CDATA[Educ. Quím]]></source>
<year>2011</year>
<volume>22</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>162-5</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ritter]]></surname>
<given-names><![CDATA[S.K]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A whole new world for rare earths]]></article-title>
<source><![CDATA[Chem Eng News]]></source>
<year>2017</year>
<volume>95</volume>
<page-range>30-4</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stevenson]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<source><![CDATA[China Faces New 'Long March' as Trade War Intensifies, Xi Jinping Says]]></source>
<year>2019</year>
<publisher-name><![CDATA[The New York Times]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stewart]]></surname>
<given-names><![CDATA[P.J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Tetrahedral and spherical representations of the periodic system]]></article-title>
<source><![CDATA[Foundations of Chemistry]]></source>
<year>2018</year>
<volume>20</volume>
<page-range>111-20</page-range></nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Topf]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<source><![CDATA[Mountain Pass sells for $20.5 million]]></source>
<year>2017</year>
<publisher-name><![CDATA[Mining. Com]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Voncken]]></surname>
<given-names><![CDATA[J.H.L]]></given-names>
</name>
</person-group>
<source><![CDATA[The Rare Earth Elements, Springer Briefs in Earth Sciences]]></source>
<year>2016</year>
<page-range>127</page-range><publisher-loc><![CDATA[Dordrecht: Springer ]]></publisher-loc>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
