Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 71 Lu 175 174.9407752(20) 0.97401(13) 174.9668(1) g 176 175.9426897(20) 0.02599(13) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page