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500
Aristotle
Aristotle says that matter is created by four different elements. Water, Fire, Earth and Air -
500
Democritus
Democritus states that Matter is created by invisible particles called "atoms." -
Period: 500 to
dates
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John Dalton
John Dalton states that atoms are small hard spheres. Atoms are invisible. Atoms of the same element are the same. Atoms of different elements are different. Atoms combine in small whole number ratios. -
Henri Becquerel and Marie & Pierre Curie
Discovered radioactivity and all three won nobel prizes in Physics -
J.J Thompson
Thompson is from England. He discovered the electron Cathode Ray Tube. Used the "Plum Pudding" example. -
Ernest Rutherford
Ernest used the Gold Foil Experiment. Discovered the Nucleus and said that is was very small, very dense and in the middle of the atom. -
Robert Millikan
In Chicago, Robert discovered the charge and mass of an electron. -
Quantum Model
Used by Niels Bohr, it structures that electrons orbit the nucleus. -
Niels Bohr
Niels used the Planetary model which states that electrons orbit the nucleus just like planets orbit the sun. -
James Chadwick
In Cambridge, James discovered the neutron.
