|Isotope||Atomic mass (Da)||Isotopic abundance (amount fraction)|
|50V||49.947 156(6)||0.002 50(10)|
|51V||50.943 957(6)||0.997 50(10)|
In its 1961 report, the Commission accepted Ar(V) = 50.942 based on mass-spectrometric data, and in 1969 recommended a more precise Ar(V) = 50.9414(3). A number of determinations of the isotopic composition of vanadium have since been considered. As a result, in 1977 the Commission refined Ar(V) to 50.9415(1). The isotopic composition of vanadium from five chondritic meteorites has been shown identical within experimental error to the terrestrial diabase W-1 and a laboratory standard.
Two stable isobars, 50Ti and 50Cr, are the immediate neighbours in the chart of nuclides, to 50V, whose β+ and β- decay modes are, therefore, predictable. The nuclear angular momentum of 50V, however, is high but consistent with long half-lives, evidently too long to be readily observed. The isobars render the mass-spectrometric determination of the abundance of the isotope 50V subject to careful chemical determination of the trace presence of Ti and Cr.
© IUPAC 2003