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First to think or make model of an atom!
sadly, all his books were burned. -
He performed experiments that proved Democritus' theory true! :)
Daltons Atomic Theory
-all matter is composed of atoms. (true)
-atoms cannot be made or destroyed.(false)
-all atoms of same element are identical. (false)
-different elements have different types of atoms. (true)
-chemical reactions occur when atoms are rearranged. (true) -
"Plum pudding model"
-first to measure the electron
-developed plum pudding model of the atom. Described the atom as a slightly positive with small electrons. -
found mass and charge of electrons. He used "oil drop" experiment.
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"Atoms have a positive nucleus." electrons are far away, circulating the nucleus. Nucleus is really tiny, but very dense. Called out "protons"
*Used gold foil experiment (which was firing particles at gold atoms and measuring their deflections) -
Created Bohr model, asked to make it by Rutherford who wasn't sure about his model.
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able to determine the size of atoms@
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Anti-Bohrs model, but not enough evidence to prove. Some believe it still today!
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expanded Bohrs model to show that electron don't always rotate on circular rings.
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Created the cloud model. Describes a cloud-like region where the electron numbers most likely found.
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Found nuetron, which is the same mass as a proton
