CHEMystery: The Periodic Table of the Elements

<BODY BGCOLOR=#000000 TEXT=#FFFFFF LINK=#FF7F00 VLINK=#00CFCF ALINK=#FFFF00> <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 93 - Neptunium (Np) <A HREF="93.wav"><IMG SRC="sound.gif" ALT="sound" BORDER=0 ALIGN=top></A></I></FONT></H1> After Neptune, the planet beyond Uranus; discovered 1940. Detected first in invisible, unweighable amounts, neptunium was the first "synthetic" element made from uranium. Traces of it turn up in uranium ores, produced by stray neutrons from uranium's decay. <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>93<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#atomicweight" TARGET="_parent">Atomic Weight</A>:</TD> <TD>237.0482<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>5s<SUP>2</SUP>5p<SUP>6</SUP>4f<SUP>14</SUP>5d<SUP>10</SUP>5f<SUP>4</SUP>6s<SUP>2</SUP>6p<SUP>6</SUP>6d<SUP>1</SUP>7s<SUP>2</SUP><BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#oxidationstate" TARGET="_parent">Oxidation States</A> (Bold most stable):</TD> <TD>+6, <B>+5</B>, +4, +3<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#boilingpoint" TARGET="_parent">Boiling Point</A> (K):</TD> <TD>4175<BR></TD> </TR> <TR> <TD>Melting Point (K):</TD> <TD>912<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#density" TARGET="_parent">Density</A> (at 300K -- g/cm<SUP>3</SUP>):</TD> <TD>20.2<BR></TD> </TR> <TR> <TD>Atomic Volume (at 300K -- cm<SUP>3</SUP>/mol) <TD>21.1<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> 236 -- 1.1 x 10<SUP>5</SUP> years -- orbital <A HREF="../reference/glossary.html#electroncapture" TARGET="_parent">electron capture</A>, <A HREF="../reference/glossary.html#betaparticle" TARGET="_parent">beta particle</A> (<A HREF="../reference/glossary.html#electron" TARGET="_parent">electron</A>) emission<BR> 237 -- 2.14 x 10<SUP>6</SUP> years -- <A HREF="../reference/glossary.html#alphaparticle" TARGET="_parent">alpha particle</A> emission<BR> 239 -- 2.346 days -- <A HREF="../reference/glossary.html#betaparticle" TARGET="_parent">beta particle</A> (<A HREF="../reference/glossary.html#electron" TARGET="_parent">electron</A>) emission<BR> </TD> </TR> <TR> <TD>Atomic Radius (Å):</TD> <TD>1.30<BR></TD> </TR> <TR> <TD>First <A HREF="../reference/glossary.html#ionizationenergy" TARGET="_parent">Ionization Potential</A> (V):</TD> <TD>5.88<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronegativity" TARGET="_parent">Electronegativity</A> (Pauling's):</TD> <TD>1.36<BR></TD> </TR> <TR> <TD>Electrical Conductivity (at 293K for polycrystalline material -- 10<SUP>6</SUP> <IMG SRC="../misc/oomega.gif" ALT="(ohms)"><SUP>-1</SUP> cm<SUP>-1</SUP>):</TD> <TD>0.8<BR></TD> </TR> <TR> <TD>Thermal Conductivity (at 300K -- W m<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>6.3<BR></TD> </TR> <TR> <TD>Crystal Structure:</TD> <TD><IMG SRC="orthorhombic.gif" ALIGN=middle> Orthorhombic<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#acid" TARGET="_parent">Acid</A>-<A HREF="../reference/glossary.html#base" TARGET="_parent">Base</A> Properties:</TD> <TD><IMG SRC="amphoteric.gif" ALIGN=middle> Amphoteric<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> </BODY>