Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 38 Sr 84 83.9134191(13) 0.0056(1) 87.62(1) g,r 86 85.9092606(12) 0.0986(1) 87 86.9088775(12) 0.0700(1) 88 87.9056125(12) 0.8258(1) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page