Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 60 Nd 142 141.9077290(20) 0.27152(40) 144.242(3) g 143 142.9098200(20) 0.12174(26) 144 143.9100930(20) 0.23798(19) 145 144.9125793(20) 0.08293(12) 146 145.9131226(20) 0.17189(32) 148 147.9168993(26) 0.05756(21) 150 149.9209022(18) 0.05638(28) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page