Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 32 Ge 70 69.92424875(90) 0.2057(27) 72.630(8) 72 71.922075826(81) 0.2745(32) 73 72.923458956(61) 0.0775(12) 74 73.921177761(13) 0.3650(20) 76 75.921402726(19) 0.0773(12) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page