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  2. Thomson problem - Wikipedia

    en.wikipedia.org/wiki/Thomson_problem

    The Thomson problem is a natural consequence of J. J. Thomson's plum pudding model in the absence of its uniform positive background charge. [ 12 ] "No fact discovered about the atom can be trivial, nor fail to accelerate the progress of physical science, for the greater part of natural philosophy is the outcome of the structure and mechanism ...

  3. J. J. Thomson - Wikipedia

    en.wikipedia.org/wiki/J._J._Thomson

    The cathode-ray tube by which J. J. Thomson demonstrated that cathode rays could be deflected by a magnetic field, and that their negative charge was not a separate phenomenon While supporters of the aetherial theory accepted the possibility that negatively charged particles are produced in Crookes tubes , [ citation needed ] they believed that ...

  4. Plum pudding model - Wikipedia

    en.wikipedia.org/wiki/Plum_pudding_model

    An atom with seven electrons arranged in a pentagonal dipyramid, as imagined by Thomson in 1905. The plum pudding model is an obsolete scientific model of the atom.It was first proposed by J. J. Thomson in 1904 following his discovery of the electron in 1897, and was rendered obsolete by Ernest Rutherford's discovery of the atomic nucleus in 1911.

  5. Cathode-ray tube - Wikipedia

    en.wikipedia.org/wiki/Cathode-ray_tube

    The voltage applied to the heater can affect the life of the CRT. [ 218 ] [ 219 ] Heating the cathode energizes the electrons in it, aiding electron emission, [ 220 ] while at the same time current is supplied to the cathode; typically anywhere from 140 mA at 1.5 V to 600 mA at 6.3 V. [ 221 ] The cathode creates an electron cloud (emits ...

  6. History of atomic theory - Wikipedia

    en.wikipedia.org/wiki/History_of_atomic_theory

    In 1898, J. J. Thomson found that the positive charge of a hydrogen ion was equal to the negative charge of a single electron. [ 70 ] In an April 1911 paper concerning his studies on alpha particle scattering, Ernest Rutherford estimated that the charge of an atomic nucleus, expressed as a multiplier of hydrogen's nuclear charge ( q e ), is ...

  7. Electron - Wikipedia

    en.wikipedia.org/wiki/Electron

    [34]: 364 [5] In the same year Emil Wiechert and Walter Kaufmann also calculated the e/m ratio but did not take the step of interpreting their results as showing a new particle, while J. J. Thomson would subsequently in 1899 give estimates for the electron charge and mass as well: e ~ 6.8 × 10 −10 esu and m ~ 3 × 10 −26 g [44] [45]

  8. Rutherford model - Wikipedia

    en.wikipedia.org/wiki/Rutherford_model

    The plum pudding model of J. J. Thomson also had rings of orbiting electrons. The Rutherford paper suggested that the central charge of an atom might be "proportional" to its atomic mass in hydrogen mass units u (roughly 1/2 of it, in Rutherford's model). For gold, this mass number is 197 (not then known to great accuracy) and was therefore ...

  9. History of mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/History_of_mass_spectrometry

    J. J. Thomson begins his study of positive rays. 1906 Thomson is awarded the Nobel Prize in Physics "in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases" 1913 Thomson is able to separate particles of different mass-to-charge ratios.