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Proposed an ¨atomic theory¨ with spherical solid atoms based upon measurable properties of mass.
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He came up with this Atomic theory as a final result of his investigation into gases. He discovered that certain gases can only be combined in certain proportions, even if two different compounds shared same element or group elements.
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Discovered cathode rays had the following properties: travel in straight lines from the cathode; cause glass to fluoresce; impart a negative charge to objects they strike; are deflected by electric fields and magnets to suggest a negative charge; cause pinwheels in their path to spin indicating they have mass.
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Used a CRT(Cathode Ray Tube) to experimentally determine the charge to mass ratio of an electron.
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Thomson's model of atomic structure is often called the plum pudding model. He postulated that the negatively charged electrons, he had recently discovered, were scattered throughout a cloud of positive charge, like the plums in plum pudding.
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Using alpha particles as atomic bullets, probed the atoms in a piece of thin gold foil . Established that the nucleus was: very dense,very small and positively charged. He also assumed that the electrons were located outside the nucleus.
Gold Foil Experiment: This experiment was determined to find out the structure of an atom. -
This model can also be called nuclear atom, or planetary model of the atom. What this model describes is that it describes the atom as a positive charged core called nucleus, tiny ,dense, in which all mass is concentrated.
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Using alpha particles discovered a neutral atomic particle with a mass close to a proton. Thus was discovered the neutron.
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Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of sucessive orbital shells of electrons.
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The atom consists of a nucleus with electrons orbiting at specific energy levels. Absorbed photons cause electrons to jump between energy levels.
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Electrons are defined as standing waves. The electron probability distribution gives the areas in which the probability of electron presence is high.
