Chemical Forums
Specialty Chemistry Forums => Nuclear Chemistry and Radiochemistry Forum => Topic started by: juanrga on April 02, 2012, 03:24:46 PM
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It seems that there are many confusion about this topic in the literature.
Some people takes nuclide as synonym of isotope. Other disagree. Also many resources discussing the difference define nuclide but then do not define isotope, but isotopes. I have tried to search the recommended IUPAC definition for isotope, but couldn't find it.
Therefore, this is my current understanding (please correct me if wrong):
Nuclide is an atom characterized by number of protons, number of neutrons and energy state.
Isotope is an atom characterized by number of protons and number of neutrons.
That is, isotope is a superclass of nuclide. Different nuclides (different energy states) are the same isotope. At the other hand we have the term isotopes.
Isotopes are a set of nuclides with equal proton number.
for example, carbon-12, carbon-13 and carbon-14 are three different isotopes of the element carbon. In its turn carbon-12 is an isotope, carbon-13 is another isotope, and carbon-14 is still another isotope.
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Effectively IUPAC do not define isotope, IUPAC only defines isotopes as a class: "Nuclides having the same atomic number but different mass numbers."
To increase the confusion about those issues, Theodore E. Brown et al. in their textbook Chemistry: The Central Science (11th Ed.) define nuclide in a completely different form as "A nuclide is a nucleus with a specified number of neutrons and protons."
A priori, I find this definition more reliable than that by IUPAC (that define nuclide as an atom) and maybe I will not follow IUPAC in those issues. Thoughts about this?