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400 BCE
Democritus, First Atomic Theory
He came up with the idea that atoms are the smallest possible form of anything. -
John Dalton, Birth
Eaglesfield, Cumbria, United Kingdom -
John Dalton Hypothesis
John Dalton hypothesized that all matter is made of atoms, and all atoms of a certain element were the same. -
John Dalton Laws
Law of Definite Proportions, Law of Multiple Proportions -
John Dalton, Death
Manchester, United Kingdom -
J.J. Thomson, Birth
Manchester, United Kingdom -
Robert Millikan, Birth
United States -
Ernest Rutherford, Birth
Brightwater, New Zealand -
Niels Bohr, Birth
Copenhagen, Denmark -
J.J. Thomson
He used a Cathode Ray tube to conclude that there are electrons in an atom that cause a negative charge, and that the number of electrons is equal to the atomic number of an atom. -
Gold Foil Experiment
Ernest Rutherford conducted the gold foil experiment to show that there are specific places that the laser bounces off of. Protons. -
Oil Drop Experiment
He used this experiment to measure electrons by the speed in which they fell. -
Ernest Rutherford Hypothesis
Ernest Rutherford hypothesized about the nucleus of an atom. -
Bohr's Model
Bohr's model was the first model to have electrons orbiting the nucleus. Proposed that energy levels of electrons are discrete. -
Robert Millikan, Nobel Prize
Physics -
Ernest Rutherford, Death
Cambridge, United Kingdom -
J.J. Thomson, Death
Cambridge, United Kingdom -
Robert Millikan, Death
United States -
Niels Bohr, Death
Copenhagen, Denmark
