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Dalton's Atomic Theory
All matter is composede of atoms. Atoms cannot be created or destroyed. Atoms of the same element are identical, Different elements have different types of atoms. Chemical reactions occur when atoms are rearranged. Compounds are formed from atoms of the constituent elements. -
J.J. Thompson: Cathode Ray Tubes
In the particle of a cathode ray tube (a tube with an eletric charge running through a wire in the center with a glow at the positive end) he found out that the charge to mass ratio was so large that the particles either carried a huge charge, or were a thousand tumes smaller than a hydrogen atom. -
Rutherford's atomic model
Rutherford created the atomic model that electrons orbit a dense, small positively-charged center of the atom called the nucleus. -
Bohr's atomic theory
Neils Bohr discovered that electrons move in set distances from the nucleus. They can only exist on certain energy levels, like certain rungs of a ladder. -
Quantum Mechanical Model
Ernest Schrodinger introduced the model with a cloud of electrons around the nucleus, including the probablity of finding an electron in a specific part.