CHEMystery: The Periodic Table of the Elements

<BODY BGCOLOR=#000000 TEXT=#FFFFFF LINK=#FF7F00 VLINK=#00CFCF ALINK=#FFFF00><script type="text/javascript" src="/banner/banner.js"></script></script><script>tql_drawTop();</script> <B><SMALL> <A HREF=".." TARGET="_parent">Return</A> to the Main CHEMystery Page.<BR> <A HREF="../pertable" TARGET="_parent">Return</A> to the Periodic Table of the Elements<BR> </SMALL></B> <H1><FONT FACE="Arial"><I>Element 85 - Astatine (At) <A HREF="85.wav"><IMG SRC="sound.gif" ALT="sound" BORDER=0 ALIGN=top></A></I></FONT></H1> From <I>astatos</I>, or unstable; discovered 1940. Astatine, prepared by bombarding bismuth atoms with helium nuclei, is radioactive and has a maximum half life of 8.1 hours. Its detection is recorded in the notebook of one of its discoveres, American physicist D.R. Corson. <HR> <CENTER><TABLE BORDER=1 CELLPADDING=2 CELLSPACING=2> <TR><TD COLSPAN=2><CENTER><H3><FONT FACE="Arial">Properties</FONT></H3></CENTER></TD></TR> <TR> <TD><A HREF="../reference/glossary.html#atomicnumber" TARGET="_parent">Atomic Number</A>:</TD> <TD>85<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#atomicweight" TARGET="_parent">Atomic Weight</A>:</TD> <TD>(210)<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronconfiguration" TARGET="_parent">Electron Configuration</A> (at ground state):</TD> <TD>1s<SUP>2</SUP>2s<SUP>2</SUP>2p<SUP>6</SUP>3s<SUP>2</SUP>3p<SUP>6</SUP>3d<SUP>10</SUP>4s<SUP>2</SUP>4p<SUP>6</SUP>4d<SUP>10</SUP>4f<SUP>14</SUP>5s<SUP>2</SUP>5p<SUP>6</SUP>5d<SUP>10</SUP>6s<SUP>2</SUP>6p<SUP>5</SUP><BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#oxidationstate" TARGET="_parent">Oxidation States</A> (Bold most stable):</TD> <TD><B>-1</B>, +1, +3, +5, +7<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#boilingpoint" TARGET="_parent">Boiling Point</A> (K):</TD> <TD>610<BR></TD> </TR> <TR> <TD>Melting Point (K):</TD> <TD>575<BR></TD> </TR> <TR> <TD>Number of natural <A HREF="../reference/glossary.html#radioactivity" TARGET="_parent">radioactive</A> isotopes:</TD> <TD>3<BR></TD> </TR> <TR> <TD> <A HREF="../reference/glossary.html#massnumber" TARGET="_parent">Mass Number</A> (Bold naturally occurring) -- <A HREF="../reference/glossary.html#halflife" TARGET="_parent">Half-Life</A> -- <A HREF="../reference/glossary.html#radioactivedisintegrationseries" TARGET="_parent">Disintigration Type</A>: </TD> <TD> 209 -- 5.4 hours -- orbital <A HREF="../reference/glossary.html#electroncapture" TARGET="_parent">electron capture</A>, <A HREF="../reference/glossary.html#alphaparticle" TARGET="_parent">alpha particle</A> emission<BR> 210 -- 8.1 hours -- orbital <A HREF="../reference/glossary.html#electroncapture" TARGET="_parent">electron capture</A><BR> 211 -- 7.21 hours -- orbital <A HREF="../reference/glossary.html#electroncapture" TARGET="_parent">electron capture</A>, <A HREF="../reference/glossary.html#alphaparticle" TARGET="_parent">alpha particle</A> emission<BR> </TD> </TR> <TR> <TD>Covalent Radius (Å):</TD> <TD>1.47<BR></TD> </TR> <TR> <TD>Atomic Radius (Å):</TD> <TD>1.45<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronegativity" TARGET="_parent">Electronegativity</A> (Pauling's):</TD> <TD>2.2<BR></TD> </TR> <TR> <TD>Heat of Vaporization (kJ/mol):</TD> <TD>30<BR></TD> </TR> <TR> <TD>Heat of Fusion (kJ/mol):</TD> <TD>12<BR></TD> </TR> <TR> <TD>Thermal Conductivity (at 300K -- W m<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>1.7<BR></TD> </TR> </TABLE></CENTER> <HR> <CENTER> <A HREF="ptbl_bar.map"><IMG SRC="ptbl_bar.gif" ALT="The Periodic Table of the Elements" BORDER=0 WIDTH=579 HEIGHT=49 ISMAP></A> </CENTER> <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-174705-4']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(ga); })(); </script></BODY>