Re: Physical properties of isotopes?

[RuthWeiner@AOL.COM]

In a message dated 9/21/01 4:30:27 PM Mountain Daylight Time, RMJones@THEITGROUP.COM writes:



> A question has been posed to me that I need help with. Can anyone come up
>
> with a reference that describes physical properties of isotopes.
>
> My limited chemistry tells me that an isotope will have the same physical
>
> properties as the elemental group the isotope belongs to. I need a good
>
> reference or correction. 
>
> Any help would be appreciated, reply to me directly.
>
> Thanks in advance. 


Your limited chemistry tells you correctly.  Isotopes of the same element have the same number of protons in the nucleus and the same number of electrons, and it is the external electrons that determine the physical and chemical properties (except for radioactive properties, which are, after all, physical properties)/.  References?  Any freshman chemistry text or elementary physcial chemistry text when discussing the propertuies of elements, or any one like me who has been teaching chemistry for about 40m years (I mean, don't we claim to KNOW anything anymore?  Does everything have to have a reference?)  The physical and chemical properties of the elements and many compounds can be found in the Handbook of Physics and Chemistry, which is published just about annually by the Chemical Rubber Company (CRC) or in a reference like Hawley's Chemical Dictionary.  Nowadays there are also web sites, I guess.


The only exception to this that I know of is the the differing atomic weights of the isotopes of hydrogen (H-1, H-2, H-3) can result in slightly different reaction rates.


Also, "isotope" is NOT a synonym for "radionuclide".  Elements of atomic number less than 92 have both radioactive and stable isotopes.


Ruth Weiner, Ph. D.

ruthweiner@aol.com