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400 BCE
Contribitors to the early model of the atom
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400 BCE
Democritus 460-370 BC
Atomos- that which cannot be cut
definition of an atom- the smallest unit of matter which still retains the identity and properties of that matter -
332 BCE
Alchemy 300 BC
Greek philosophers became interested in Egyptian religion. Greeks combined the theory of the four elements and religion -
300 BCE
Aristotle 384-322 BC
Only believed in four elements: earth,fire,water and air
Because Aristotle refuted Democritus he caused 2000 years of bogus science. -
Phlogiston Theory
Means "burning up"
Founded by Johann Joachim Becher
Carbon Dioxide that was no longer burning is called "dephlogisticated air" -
Benjamin Franklin
Discovered electrical charges come in 2 varieties- positive and negative -
Anton Laurent de La Voisier (1743-1794)
Father of modern chemistry
Discovered oxygen causes combustion
Discovered the law of conservstion of mass
Also discovered that matter cannot be destroyed or created in a chemical reaction -
John Dalton "father of atomic theory" (1766-1844)
Dalton's Atomic theory of matter -
James Joule
Conducted the paddle wheel experiment.
Placed the wheel in CRT and sent a charge through the wheel, it started spinning. -
JJ Thomson
Conducted the CRT experiment
CRT- a glass tube that contains no air and coated in fluorescent paint and when a charge is sent through the paint, it glows, indicating radiation -
Ernest Rutherford
Discovered the classification of radiation -
Becquerel
Discovered radiation -
Marie and Pierre Curie
Isolated polonium and radium from Uranium ores -
Milikan
Calculated the charge and mass of an electron -
Famous gold foil experiment
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James Chadwick
Discovered neutrons
