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100
Democritus (400b.c.)
Democritus said the atom existed. he thought that if a substance is broken down to its smallest where you can't break anymore i an atom. He got it from theories from observations. He thought you can not eliminate atoms. They differ sizes, shape, and temperature. -
Period: 100 to
History of an Atom Timeline
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John Dalton
He said that a chemical reactions are responsible for rearranging the combinationss of atom. Everything consists of atoms. he made his discovery byusing mathematical models. He thought atosms has a compound. He thought all atoms formed to make an element has the same mass -
J.J Thomson
He had founded electrons and that an atom can be divided. He gathered evidence from experiments. He thought the electrons are barricaded by positive charge to even out negative charges. Call the Plum Pudding model. -
Lord Rutherford
He found that if most of the mass was compacted in the nucleus. the alpha partices can be deflected. He gather information from experiments. He thought the atom protons are in the nucleus and the electrons orbited around it. -
Niels Bohr
He thought electrons can ahve orbits around the nucleus. He thought electrons must stay in a continous orbit around the nucleus. He made his dicovery by theories from observation. He thought that the electrons go in an orbit. -
Heisenberg and Schrodinger
They thought that what ever you do you can't measure the position and momentum of a quantum particle. They made their discivery by matematical models. They thought that the nucleus was surrounded by an electron cloud.
