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300
Aristotle (300 BC)
He claimed that each of the four primary elements propoed by Empedocles could be charged into any other element by adding or removing and moisture.Learned from Empedocles and did not believe in the atoms theory he believed in the four elements."Atomic Theory." Atomic Theory. N.p., n.d. Web. 27 Feb. 2014. http://clickandlearn.org/Gr9_Sci/atoms/modelsoftheatom.html. -
450
Democritus (400BC)
He held that all things were composed of atoms. These he asserted to be tiny particles imperceptible to the senses, composed of exactly the same underived,and indestructable. He added onto Leucippus.He believed all sensation is formvof touch resulting from atoms colliding with the sense organs. Marble is what he thought the atom looked like. Atom, the invisible particle."Electron." EBSCO. Columbia University Press, n.d. Web. <http://web.b.ebscohost.com/src/detail?vid=4&sid=96214689-893c-4654-9b5 -
Dalton
Each chemical element is composed pf its own kind of atoms, all with the same relative weight. His theory propesed a number of basic ideas like " all matter is compoed of atoms,"and also,"Atom cannot be made or destroyed." Explains chemical change better than the Partical Theory.Http://smallcontent.ebsco-content.com/interfacefiles/14.1.0.78/src/logoSRC.gif. Http://smallcontent.ebsco-content.com/interfacefiles/14.1.0.78/src/logoSRC.gif, n.d. Web. -
Thomas
Showed that cathode rays are composed of eletrons and who measured the ratio of charged to mass for the electron proton.Fundamentals building blocks of matter. ''The Raisin in the Pudding" model.Http://smallcontent.ebsco-content.com/interfacefiles/14.1.0.78/src/logoSRC.gif. Http://smallcontent.ebsco-content.com/interfacefiles/14.1.0.78/src/logoSRC.gif, n.d. Web. -
Rutherford
All the mass of an Atom is concentrated in a tiny nucleas. The nuclears is surrounded by eletrons traveling at tremendous speed through the atom outer regions. Theory of Atomic Structure."World Book Online Reference Center." World Book. N.p., n.d. Web. 27 Feb. 2014. http://www.worldbookonline.com/student/article?id=ar036320&st=rutherford%27s+atomic+theory. -
Bohr
He aided a theory by the German physicist Max Planck.Was based on an earlier one propoed by Ernest Rutherford. Bohr proposed that the eletrons could travel only in certain successively larger orbits could hold more eletrons in the outmost orbit determined the atom's chemical proporties.Http://smallcontent.ebsco-content.com/interfacefiles/14.1.0.78/src/logoSRC.gif. Http://smallcontent.ebsco-content.com/interfacefiles/14.1.0.78/src/logoSRC.gif, n.d. Web. -
Heisenberg and schrodinger
He discovered the mathmatical equation describing the wavelike behavior of atomic particles.The equation was also known as the Schroginger equation is based on a french physiatrist."Atomic Theory." Atomic Theory. N.p., n.d. Web. 27 Feb. 2014. http://clickandlearn.org/Gr9_Sci/atoms/modelsoftheatom.html.
