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101
Thales of Miletus- 620 B.C.
-1st person to incestigate dbasic principles of atoms -
102
Democritus- 440 B.C.E.
-"Cutting The Cheese" (mental experiment)
-Cut an object until it couldn't get any smaller, the smallest would be an atom -
103
Aristotle- 340 B.C.E.
-Didn't believe in atomic theory
-Believed in earth, wind, fire, water element -
Sir Isaac Newton
-Contribuuted to the idea that atoms are held together by attractions or forces. -
Dalton
-Atomic Theory Experiment
1. All matter is made up of tiny particles called atoms
2. All atoms of a given element are alike, but are different from the atoms of any other element
3. Compounds are formed when atoms of different elements combine in fixed proportions
4. A chemical reaction involves a rearrangment of atoms, hot a change in the atoms themselves. -
Henri Besquerel
-Uraium experiment
-Discovered radio activity -
JJ Thomson
-Plum-Pudding model
-Discovered the election -
Robert Millikan
-Oil drip experiment
-Found charge of indivdual electrons -
Ernest Rutherrford
-Gold-Foil experiment
-Theorized that the atom was mostly empty space and that all positive charge was found in the nucleus
-Discovered the nucleus and the proton -
Niels Bohr
-Primitive hydrogen model -
Francis Aston
-Experiment-Mass spectograph
-Discovered isotopes -
Gold-Foil Experiment
-Rutherford performed it
-Was used to discovet he proton and nucleus -
James Chadwick
Discoverd the Neutron
