Discusses four key scientific experiments performed between 1870 and 1940 which established the structure of the atom. Features Thompson's plum pudding model, Rutherford's gold foil experiment, the Bohr model, and the orbitals and quantum mechanical model.Identifies the fundamental atomic particles which led to the present nuclear model of the atom used by chemists, discussing the concept of a scientific model derived by experiment. Illustrates the way a cathode tube works and demonstrates the features of a mass spectrometer. Concludes with atomic notation and its use to represent isotopes.

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