Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 74 W 180 179.9467108(20) 0.0012(1) 183.84(1) 182 181.94820394(91) 0.2650(16) 183 182.95022275(90) 0.1431(4) 184 183.95093092(94) 0.3064(2) 186 185.9543628(17) 0.2843(19) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page