AUTHORAston, F. W.
TITLEIsotope and Atomic Weights
PERIODICAL TITLENature
DATE PUBLISHED1920
VOLUME NUMBER105
ISSUE NUMBER
PAGE NUMBERS617
ISSN0028-0836
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This short, seminal article by physicist F.W. Aston describes the determination of atomic masses using an early mass spectrometer. Those measurements validated Frederick Soddy's theory of isotopes. Aston briefly reviews the development of atomic theory beginning with John Dalton in 1801. He quotes from an address by William Ramsay in 1897, which stated that atomic weights of elements may represent averages rather than constants, then he describes the work of Ernest Rutherford, Frederick Soddy, and J.J. Thomson and the gradual development of the isotope theory. Lastly, he describes how atomic masses are measured in a mass spectrometer using positive ions and how those measurements indicate the presence of isotopes.


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