Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 36 Kr 78 77.92036494(76) 0.00355(3) 83.798(2) g,m 80 79.91637808(75) 0.02286(10) 82 81.91348273(94) 0.11593(31) 83 82.91412716(32) 0.11500(19) 84 83.9114977282(44) 0.56987(15) 86 85.9106106269(41) 0.17279(41) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page