Atomic Weights and Isotopic Compositions for Mendelevium
Column Descriptions

                                                                         
             Relative           Isotopic      Standard                   
Isotope      Atomic Mass        Composition   Atomic Weight    Notes     
_________________________________________________________________________
101 Md  258  258.0984315(50)                               
        260  260.10365(34#)                 
_________________________________________________________________________

NIST | Physical Measurement Laboratory | Physical Reference Data | Atomic Weights and Isotopic Compositions Main Page