jan 1, 1913 - Henry Moseley published
the results of his
"measurements of
wavelengths of the x-ray
spectral lines of a number
of elements which showed
that the ordering of the
wavelengths of the x-ray
emissions of the elements
coincided with the ordering
of the elements by atomic
number." With more discoveries
they learned that atomic weight
was not as important as they
thought.
