HIST 22 |
| This presentation will review some of the evidence for the divisibility and impermanence of atoms accumulated in the late 19th and early 20th centuries. When J. J. Thomson characterized cathode rays in 1897 as light, negatively charged “corpuscles,” he proposed that they were a universal constituent of atoms. The discovery of radioactivity by Henri Becquerel in 1896 opened lines of inquiry quickly developed by Marie Curie and Ernest Rutherford among others. Within a decade, it was apparent that some atoms lost pieces spontaneously, turning into smaller atoms. Within a few more years came evidence that most of the atom's mass was concentrated in a minuscule volume. In retrospect, these researchers provided strong evidence that matter is ultimately discrete and particulate, but that atoms are not the ultimate particles. |
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200 Years of Atoms in Chemistry: From Dalton’s Atoms to Nanotechnology
8:45 AM-12:00 PM, Tuesday, August 19, 2008 Hilton Garden Inn -- Salon B, Oral
Sci-Mix
Division of the History of Chemistry |