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400 BCE
Democritus
- said everything is composed of atoms
- imaged the fisrt sight of an atom
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400 BCE
Plato
- ideal geometric forms seve as atoms
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1197
JJ Thompson
- discovered the electron
- all matter is made of a particle smaller than an atom
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1400
The alchemists
- treated metal and ores to try and create gold
- created a scientific theory that would be used to discover an atom
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Robert Boyle
- created a theory that matter is composed of tiny particles
- exposed chemical changes
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John Dalton
- suggested that all matter is made of tiny particles called atoms
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Amedeo avogadro
- contributed to the atomic theory that elemental gasses have equal number of molecules and are made of two elements
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Dmitri Mendeleev
- made the first periodic table
- discovered elements not yet found in the wild
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Pierre and Marie Curie
- Conducted experiments with radiology and discovered palomuim and Raduim.
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Albert Einsten
- math proved the existence of atoms and their random motion
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Robert millikan
- figured out the charge of an electron
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Ernest Rutherford
- reacherched atomic and nuclear physics
- added scientific ideas about atoms
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neils bohr
- atomic theory states that an atom is like a planetery model because it orbits the center.
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Henry G.J Mosley
- discovered the atomic number of the elements.
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James Chadwich
- discovered neutrons