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View Full Version : Q: ionic radii of different isotopes

Feed_me_spam
Jul25-04, 08:16 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nHi,\nthe nuclei of different isotopes of an element have slightly different\nshapes and should hence display slight differences in their charge\ndistribution. I was wondering if this difference also affects the\norbitals and the atomic/ionic radii in a very subtle way (especially\nat low Z) and if this effect, if it exists, can be detected. I did a\nweb search, but found no radius values where a distinction between\ndifferent isotopes was made. Any references or explanations would be\nwelcome.\nThanks,\nTom\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>Hi,
the nuclei of different isotopes of an element have slightly different
shapes and should hence display slight differences in their charge
distribution. I was wondering if this difference also affects the
orbitals and the atomic/ionic radii in a very subtle way (especially
at low Z) and if this effect, if it exists, can be detected. I did a
web search, but found no radius values where a distinction between
different isotopes was made. Any references or explanations would be
welcome.
Thanks,
Tom
Uncle Al
Jul25-04, 10:09 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nFeed_me_spam wrote:\n&gt;\n&gt; Hi,\n&gt; the nuclei of different isotopes of an element have slightly different\n&gt; shapes and should hence display slight differences in their charge\n&gt; distribution. I was wondering if this difference also affects the\n&gt; orbitals and the atomic/ionic radii in a very subtle way (especially\n&gt; at low Z) and if this effect, if it exists, can be detected. I did a\n&gt; web search, but found no radius values where a distinction between\n&gt; different isotopes was made. Any references or explanations would be\n&gt; welcome.\n\nIt isn\'t subtle. Different low-Z isotopes can exhibit major\nthermodynamic differences in chemistry. An isolated atom has\nsubstantial isotope shifts in its spectroscopy. Changing the\nspin or qaudrupole moment of an isotopc nucleus will change the\nhyperfine levels - energies and degeneracies - in the electron\norbitals.\n\nHeavy atoms have Z^5 Weak Interaction and large relativistic\nanomalies.\n\n--\nUncle Al\nhttp://www.mazepath.com/uncleal/\n(Toxic URL! Unsafe for children and most mammals)\nhttp://www.mazepath.com/uncleal/qz.pdf\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>Feed_me_spam wrote:
>
> Hi,
> the nuclei of different isotopes of an element have slightly different
> shapes and should hence display slight differences in their charge
> distribution. I was wondering if this difference also affects the
> orbitals and the atomic/ionic radii in a very subtle way (especially
> at low Z) and if this effect, if it exists, can be detected. I did a
> web search, but found no radius values where a distinction between
> different isotopes was made. Any references or explanations would be
> welcome.

It isn't subtle. Different low-Z isotopes can exhibit major
thermodynamic differences in chemistry. An isolated atom has
substantial isotope shifts in its spectroscopy. Changing the
spin or qaudrupole moment of an isotopc nucleus will change the
hyperfine levels - energies and degeneracies - in the electron
orbitals.

Heavy atoms have Z^5 Weak Interaction and large relativistic
anomalies.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf