-
300
Aristotle (300 BC)
He slowed the Atomic Theory by disagreeing with Democritus -
300
Aristotle
-
400
Democritus of Adbera (400 BC)
He was the first to propose any type of atmomic theory. He believed everything had "atomos." -
400
democritus of adbera
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500
Alchemists (500 BC)
Alchemists developed the theory that all metals are composed of mercury and sulfur and that its possible to change base metals into gold. -
500
alchemists
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Benjamin Franklin
He developed the idea that matter had positive and negative charges -
Ben Franklin
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Antoine Lavoisier
He began the controversy on exactly an atom is -
Joseph Proust
He proposed the Law of Constant Composition. -
Joseph Proust
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John Dalton
He created Dalton's theory. Some of his theory is still being used in chemistry today. -
John Dalton
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Michael Faraday
He suggested that the structure of the atom relates to electricity -
Max Planck
He was the founder of the Quantum Theory that focuses on the nature of matter -
Max Planck
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Dmitri Mendeleev
He came up with the first design of the Periodic Table Of Elements. -
Dmitri Mendeleev
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William Crookes
He reconstructed the cathode ray and showed there is a negative charge in atoms -
Henry Becquerel
He discovered radioactivity -
Henry Becquerel
-
Joseph John Thomson
He discovered the electron -
Joseph John Thomson
-
Marie and Pierre Curie
They discovered polonium and radium. Both of those were radioactive elements -
Marie Pierre Curie
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Albert Einstein
He published the famous equation E=mc^2 -
Robert Millikan
He used the oil drop experiment and determined the charge and mass of an electron -
Robert Millikan
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Ernest Rutherford* (different dates)
He came to the conclusion that an atom has a dense and charged nucleus with electrons floating randomly around the nucleus. -
Ernest Rutherford*(Different dates)
He came to the conclusion that an atom has a dense and charged nucleus with electrons floating randomly around the nucleus. -
Niels Bohr
He made the bohr model which had electrons around the nucleus. H egave us the understanding of why atoms bond and how they stay the same. -
Niels Bohr
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Louis deBroglie
He said that moving particles in an atom have some properties of waves. -
Louis deBroglie
-
Warner Heisenberg
He founded quantum mechanics that was used to interpretating the behavior of atoms -
Werner Heisenberg
-
Erwin Schrodinger
He develpoed mathematical equations that describe the motion of an atom which lef to the electron cloud model -
erwin schrodinger
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James Chadwick
He discovered neutrons -
James Chadwick
