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 77 - Iridium (Ir) <A HREF="77.wav"><IMG SRC="sound.gif" ALT="sound" BORDER=0 ALIGN=top></A></I></FONT></H1> From <I>iris</I>, or rainbow, so named for its colorful salts; discovered 1804. Very hard and hence extremely difficult to work or cast, iridium hardens other metals. Its alloys make bars used as standard weights and measures. The international "standard meter" is platinum-iridium <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>77<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#atomicweight" TARGET="_parent">Atomic Weight</A>:</TD> <TD>192.22<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>7</SUP>6s<SUP>2</SUP><BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#oxidationstate" TARGET="_parent">Oxidation States</A> (Bold most stable):</TD> <TD>+2, +3, <B>+4</B>, +6<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#boilingpoint" TARGET="_parent">Boiling Point</A> (K):</TD> <TD>4700<BR></TD> </TR> <TR> <TD>Melting Point (K):</TD> <TD>2720<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#density" TARGET="_parent">Density</A> (at 300K -- g/cm<SUP>3</SUP>):</TD> <TD>22.6<BR></TD> </TR> <TR> <TD>Atomic Volume (at 300K -- cm<SUP>3</SUP>/mol) <TD>8.54<BR></TD> </TR> <TR> <TD>Number of stable <A HREF="../reference/glossary.html#isotopes" TARGET="_parent">isotopes</A>:</TD> <TD>2<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> 192 -- 74.2 days -- <A HREF="../reference/glossary.html#betaparticle" TARGET="_parent">beta particle</A> (<A HREF="../reference/glossary.html#electron" TARGET="_parent">electron</A>) emission<BR>, <A HREF="../reference/glossary.html#positron" TARGET="_parent">positron</A> emission, orbital <A HREF="../reference/glossary.html#electroncapture" TARGET="_parent">electron capture</A><BR> </TD> </TR> <TR> <TD>Covalent Radius (Å):</TD> <TD>1.27<BR></TD> </TR> <TR> <TD>Atomic Radius (Å):</TD> <TD>1.36<BR></TD> </TR> <TR> <TD>First <A HREF="../reference/glossary.html#ionizationenergy" TARGET="_parent">Ionization Potential</A> (V):</TD> <TD>9.1<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronegativity" TARGET="_parent">Electronegativity</A> (Pauling's):</TD> <TD>2.20<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#specificheat" TARGET="_parent">Specific Heat</A> Capacity (at 300K -- J g<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>0.130<BR></TD> </TR> <TR> <TD>Heat of Vaporization (kJ/mol):</TD> <TD>563.58<BR></TD> </TR> <TR> <TD>Heat of Fusion (kJ/mol):</TD> <TD>26.36<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>21.3<BR></TD> </TR> <TR> <TD>Thermal Conductivity (at 300K -- W m<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>147<BR></TD> </TR> <TR> <TD>Crystal Structure:</TD> <TD><IMG SRC="cubic-face.gif" ALIGN=middle> Cubic, face centered<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="very-basic.gif" ALIGN=middle> Very basic<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>