Column Descriptions

                                                                         
             Relative           Isotopic      Standard                   
Isotope      Atomic Mass        Composition   Atomic Weight    Notes     
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14  Si  28   27.97692653465(44)  0.92223(19)   [28.084,28.086]   
        29   28.97649466490(52)  0.04685(8)  
        30   29.973770136(23)   0.03092(11) 
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