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Democritus
Theorized that everything is made of indivisible particles. He called them atomos. He was a student of socrates. He is considered to be the father of modern science. -
John Dalton
Daltons Postulates
1. Everything is made of atoms
2. Atoms cannot be broken down
Democritus first suggested the existence of the atom but it took almost two millennia before the atom was placed on a solid foothold as a fundamental chemical object by John Dalton. -
JJ Thompson
Discovered the electron. He made the plum pudding model or the chocolate chip cookie.His work put forward a new theory, that atom was made up of small particles.Thomson discovered the electrons and it was proved that atoms were made up of protons, electrons and neutrons. -
Earnest Rutherford
Dicovered that atoms mostly empty space with a small, dense, positive nucleus in the center of it. He did the Gold Foil Experiment. -
Neils Bohr
Seperated electrons into energy levels. He made the Bohr Model. Suggested that most of the mass of the atom was contained in the small nucleus.Rutherford found that although the vast majority of particles passed straight through the foil approximately 1 in 8000 were deflected leading him to his theory that most of the atom was made up of 'empty space'. -
Quantum Theory or Modern Theory
They dicovered neutron, isotopes, and the uncertainty principle. Many scientists made the theory. Philosophical implications of the seemingly harmless sounding uncertainty relations, physicists speak of an uncertainty principle, which is often called more descriptively the "principle of indeterminacy."
