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 72 - Hafnium (Hf) <A HREF="72.wav"><IMG SRC="sound.gif" ALT="sound" BORDER=0 ALIGN=top></A></I></FONT></H1> From <I>Hafnia</I>, the Latin name for Copenhagen; discovered 1923. A "wonder metal" of the atomic age, hafnium has a great appetite for neutrons. Thus it goes into neutron-absorbing reactor control rods which slow down nuclear chain reactions and also quench atomic "fires." <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>72<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#atomicweight" TARGET="_parent">Atomic Weight</A>:</TD> <TD>178.49<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>2</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><B>+4</B><BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#boilingpoint" TARGET="_parent">Boiling Point</A> (K):</TD> <TD>4875<BR></TD> </TR> <TR> <TD>Melting Point (K):</TD> <TD>2504<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#density" TARGET="_parent">Density</A> (at 300K -- g/cm<SUP>3</SUP>):</TD> <TD>13.31<BR></TD> </TR> <TR> <TD>Atomic Volume (at 300K -- cm<SUP>3</SUP>/mol) <TD>13.6<BR></TD> </TR> <TR> <TD>Number of stable <A HREF="../reference/glossary.html#isotopes" TARGET="_parent">isotopes</A>:</TD> <TD>6<BR></TD> </TR> <TR> <TD>Covalent Radius (Å):</TD> <TD>1.44<BR></TD> </TR> <TR> <TD>Atomic Radius (Å):</TD> <TD>1.67<BR></TD> </TR> <TR> <TD>First <A HREF="../reference/glossary.html#ionizationenergy" TARGET="_parent">Ionization Potential</A> (V):</TD> <TD>6.65<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronegativity" TARGET="_parent">Electronegativity</A> (Pauling's):</TD> <TD>1.3<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>0.14<BR></TD> </TR> <TR> <TD>Heat of Vaporization (kJ/mol):</TD> <TD>661.07<BR></TD> </TR> <TR> <TD>Heat of Fusion (kJ/mol):</TD> <TD>21.76<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>3.4<BR></TD> </TR> <TR> <TD>Thermal Conductivity (at 300K -- W m<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>23.0<BR></TD> </TR> <TR> <TD>Crystal Structure:</TD> <TD><IMG SRC="hexagonal.gif" ALIGN=middle> Hexagonal<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> <A HREF="../reference/glossary.html#amphotericoxide" TARGET="_parent">Amphoteric</A><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>