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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 ...
J.J. Thomson (1897) "Cathode Rays", The Electrician 39, 104, also published in Proceedings of the Royal Institution 30 April 1897, 1–14 – first announcement of the "corpuscle" (before the classic mass and charge experiment) J.J. Thomson (1897), Cathode rays, Philosophical Magazine, 44, 293 – the classic measurement of the electron mass ...
1897 – J. J. Thomson's experimentation with cathode rays led him to suggest a fundamental unit more than a 1000 times smaller than an atom, based on the high charge-to-mass ratio. He called the particle a "corpuscle", but later scientists preferred the term electron. [52]
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.
If Thomson was correct, the beam would go through the gold foil with very small deflections. In the experiment most of the beam passed through the foil, but a few were deflected. [6] In a May 1911 paper, [7] Rutherford presented his own physical model for subatomic structure, as an interpretation for the unexpected experimental results. [2]
The electron was discovered between 1879 and 1897 in works of William Crookes, Arthur Schuster, J. J. Thomson, and other physicists; its charge was carefully measured by Robert Andrews Millikan and Harvey Fletcher in their oil drop experiment of 1909.
This is a timeline of subatomic particle discoveries, including all particles thus far discovered which appear to be elementary (that is, indivisible) given the best available evidence. It also includes the discovery of composite particles and antiparticles that were of particular historical importance.
1897 J. J. Thomson discovered the electron; 1897 Emil Wiechert, Walter Kaufmann and J.J. Thomson discover the electron; 1898 Marie and Pierre Curie discovered the existence of the radioactive elements radium and polonium in their research of pitchblende; 1898 William Ramsay and Morris Travers discover neon, and negatively charged beta particles