can you elaborate on the initial physicist's theory?
He formulated the Rutherford model of the atom in 1911 that a very small charged nucleus, containing much of the atom's mass, was orbited by low-mass electrons.
Ernest Rutherford
It was Rutherford's interpretation of this data that led him to formulate the Rutherford model of the atom in 1911that a very small charged nucleus, containing much of the atom's mass, was orbited by low-mass electrons.
a medium of free floating positive and negative charges is called a(n) Plasma what can you tell me about the physical properties of electron? The electric charge is negative one elementary charge; its mass is approximately 1/1836 that of the proton; exhibit properties of both particles and waves: they can collide with other particles and can be diffracted like light. where can you see its use? In the electron microscope; free-electron laser (FEL); cathode ray tubes; in welding;  Electron beam processing is used to irradiate materials in order to change their physical properties or sterilize medical and food products. were there any theories based on it? Yes - experiments by physicists Ernest Rutherford, Henry Moseley, James Franck and Gustav Hertz had largely established the structure of an atom as a dense nucleus of positive charge surrounded by lower-mass electrons.
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Ernest Rutherford [SEP] Gold foil experiment
Rutherford performed his most famous work after receiving the Nobel prize in 1908. Along with Hans Geiger and Ernest Marsden in 1909, he carried out the Geiger–Marsden experiment, which demonstrated the nuclear nature of atoms by deflecting alpha particles passing through a thin gold foil. Rutherford was inspired to ask Geiger and Marsden in this experiment to look for alpha particles with very high deflection angles, of a type not expected from any theory of matter at that time. Such deflections, though rare, were found, and proved to be a smooth but high-order function of the deflection angle. It was Rutherford's interpretation of this data that led him to formulate the Rutherford model of the atom in 1911that a very small charged nucleus, containing much of the atom's mass, was orbited by low-mass electrons.