The flashcards below were created by user
annasch95
on FreezingBlue Flashcards.
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democritus
- 400bc
- world made of tiny INDIVISABLE particles called atomos.
- not experimental
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dalton
- early 1800s
- each element composed of small particles called atoms
- all atoms of a given element are identical to one another in mass and properties
- atoms not changed durring reactions (not created or destroyed)
- compounds formed when more than one element combine; compunds always have same relative number and kinds of atoms
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law of constant composition
- dalton
- relative number and kinds of atoms constant in compound
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law of conservation of mass or matter
- dalton
- atoms neither created nor destroyed
- mass before=mass after reaction
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law of multiple proportions
- two elements can combine in different proportions but they mae different compounds
- dalton
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fundamental principal in chem
particles with same charge repel, opposite attract
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jj thompson
- late 1800s
- discovered electrons aka smaller than atom things
- didn't see them but caused cathodes to flouresce
- how tv work
- also calculated charge to mass ratio
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robert millikan
- 1909
- measured electron charge by seeing that data was multiples of the charge
- oil drop experiment
- could determine mass with thompson's calculations
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marie curie
- discovered radioactivity
- spontaneous emmision of radioactive isotopes
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ernest rutherford
- discovered alpha, beta, gama rays because of diff response to electric field
- disproved jj thompson's plumb puding model
- determined that nucleus was small, dense, positive, atom 10000 larger than nucleus
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gold foil experiment
- rutherford
- passed alpha particles through gold sheet
- most went through, some deflected
- discovered protons
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discovered neutrons
james chadwick
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