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Leucippus and Democritus
The first proponents of an atomic theory were the Greek philosophers Leucippus and Democritus who proposed the following model in the fifth century B.C. 1. Matter is composed of atoms separated by empty space through which the atoms move. Atoms are solid, homogeneous, indivisible, and unchangeable. -
Antoine Lavoisier
Antoine Lavoisier (1743-1794) was the first person to make good use of the balance. He was an excellent experimenter. After a visit with Priestly in 1774, he began careful study of the burning process. He proposed the Combustion Theory which was based on sound mass measurements. He also proposed the law of concentration of mass it states that even if matter changes shape or form, its mass stays the same. -
James Dalton
The main points of Dalton's atomic theory are: Elements are made of extremely small particles called atoms. Atoms of a given element are identical in size, mass and other properties; atoms of different elements differ in size, mass and other properties. Atoms cannot be subdivided, created or destroyed. -
Eungene Goldstein
He discovered protons with the experiments he did with cathode rays which would knock electrons of atoms and attract them to a positively charged electrode. -
J.J. Thompson
English physist J.J. Thompson took the discharge tube research further, by measuring how much heat the cathode rays generated how much they could be bent by magnets and other other things he was able to estimate the mass of the rays and other things he was able to estimate the mass of the rays
Plum pudding model the positive matrix being the cake, and the electrons being the floating bits. -
Ernest Rutherford
Rutherford overturned Thomson's model in 1911 with his well-known gold foil experiment in which he demonstrated that the atom has a tiny and heavy nucleus. Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure. -
Niels Borg
The Rutherford Bohr model or Bohr model or Bohr diagram, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by revolving electrons similar to the structure of the Solar System, but with attraction provided by electrostatic forces rather -
Werner Heinsenberg
Werner Heisenberg was a German theoretical physicist who made foundational contributions to quantum theory
(proposes that electrons weren't particles waves, instead, they had propertiesof both and neither). It was also in Copenhagen that Heisenberg developed his famous uncertainty principle, which he first described in a letter to Wolfgang Pauli
