Column Descriptions Relative Isotopic Standard Isotope Atomic Mass Composition Atomic Weight Notes _________________________________________________________________________ 80 Hg 196 195.9658326(32) 0.0015(1) 200.592(3) 198 197.96676860(52) 0.0997(20) 199 198.96828064(46) 0.1687(22) 200 199.96832659(47) 0.2310(19) 201 200.97030284(69) 0.1318(9) 202 201.97064340(69) 0.2986(26) 204 203.97349398(53) 0.0687(15) _________________________________________________________________________NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page