Acommon isotope of Carbon has an atomic number of and a mass number of 13. How many neutrons are in A 6 an atom of this isotope?

1 Answer
Sep 5, 2016

Answer:

There are necessarily #7# neutrons in the #""^13C# isotope.

Explanation:

All carbon nuclei contain 6 nuclear protons; i.e 6 positively charged, massive nuclear particles. Were there a different number than 6, then we could not call it a carbon isotope, i.e for the #C# nucleus, #Z=6#.

Most carbon nuclei also contain 6 neutrons, 6 massive, neutrally charged nuclear particles; i.e. the #""^12C# isotope. A few carbon nuclei contain 7 neutrons rather than 6 to give the #""^13C# isotope; the isotopic abundance is approx. 1.1%.

Chemists can now routinely take advantage of the magnetic properties of the #""^13C# isotope by means of #""^13C{""^1H}# #"NMR spectroscopy"#. This is a bit less sensitive than #""^1H# #"NMR spectroscopy"#, and a bit of a longer experiment, but it is a direct method of analysis, and characterization of a new organic molecule would routinely demand details of its #""^13C{""^1H}# #"NMR spectrum"#.