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Period: to
AD
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John Dalton
Dalton thought that atoms were indestructible balls without an internal structure. -
Beginning of the California Gold Rush
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Civil War
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J.J. Thomson
Discovered the electron. After which he developed the plum pudding model. -
Max Planck
Discovered that the energy in light is directly proportional to the frequency. -
Earnest Rutherford
Found that the nucleus is a dense, positively charged ball in center of an atom. -
Niels Bohr
Bohr created a model in which electrons move in fixed orbits about the nucleus like planets around the sun. -
Beginning of WW1
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Robert Millikan
Carried out experiments to find the quantity of charge carried by an electron. Using the value he obtained in his experiments he then used the charge-to-mass ratio developed by Thompson, He was then able to figure out the mass of an electron. -
Louis de Broglie
Broglie proposed that particles like electrons have some properties of waves. Experimental data supports this theory. -
Erwin Schrodinger
Schrodinger develops equations that predict the motion of electrons in an atom, leading to the development of the Electron Cloud Model (Quantum Mechanic Model). -
Warner Heisenberg
Created the Heisenberg Uncertainty Principle, which states that it is impossible to know the velocity and position of a sub-atomic particle at the same time. -
Beginning of Great Depression
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James Chadwick
Chadwick confirmed the existence of neutrons in the nucleus of the atom. -
Pearl Harbour