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An atom with seven electrons arranged in a pentagonal dipyramid, as imagined by Thomson in 1905. The plum pudding model was the first scientific model of the atom to describe an internal structure.
Sir Joseph John Thomson (18 December 1856 ... and that the corpuscles were their building blocks. In 1904, Thomson suggested a model of the atom, ...
The prevailing model of atomic structure before Rutherford's experiments was devised by J. J. Thomson. [1]: 123 Thomson had discovered the electron through his work on cathode rays [2] and proposed that they existed within atoms, and an electric current is electrons hopping from one atom to an adjacent one in a series.
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 ...
Electron discovered by J. J. Thomson [4] 1899 Alpha particle discovered by Ernest Rutherford in uranium radiation [5] 1900 Gamma ray (a high-energy photon) discovered by Paul Villard in uranium decay [6] 1911 Atomic nucleus identified by Ernest Rutherford, based on scattering observed by Hans Geiger and Ernest Marsden [7] 1919
1904 – J. J. Thomson's plum pudding model of the atom 1904; 1905 – Albert Einstein: Special relativity, proposes light quantum (later named photon) to explain the photoelectric effect, Brownian motion, Mass–energy equivalence; 1908 – Hermann Minkowski: Minkowski space; 1911 – Ernest Rutherford: Discovery of the atomic nucleus ...
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
Thomson's model was incomplete, it could not predict any of the known properties of the atom such as emission spectra or valencies. In 1906, Robert A. Millikan and Harvey Fletcher performed the oil drop experiment in which they measured the charge of an electron to be about -1.6 × 10 -19 , a value now defined as -1 e .