It could be added that atomic weight is often not truly atomic either, as it does not correspond to the property of any individual atom.
These radicals have low atomic weights while the persulfate molecule has a high atomic weight (238).
The groups are horizontal, the elements are in order of increasing atomic weight and there are vacant slots for undiscovered ones.
Hydrogen-1, the lightest isotope of hydrogen and the atom with the lowest mass, has an atomic weight of 1.007825 u.
Work on organizing the elements by atomic weight had hitherto been stymied by inaccurate measurements of the atomic weights.
However, as noted in the introduction, atomic weight and standard atomic weight represent terms for averages of isotopic abundances, not for single nuclides.
However, atomic weight, ie, relative atomic mass, is a dimensionless quantity, and can not take the units of grams per mole.
Her research focus was on aromatic acids and the atomic weight of palladium.