Column Descriptions

                                                                         
             Relative           Isotopic      Standard                   
Isotope      Atomic Mass        Composition   Atomic Weight    Notes     
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7   N   14   14.00307400443(20)  0.99636(20)   [14.00643,14.00728]   
        15   15.00010889888(64)  0.00364(20) 
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