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First Idea Of Atoms-First Atom Theory
The Greek philosopher Democritus came up with the first idea of what an atom looks like in 450 B.C. along with the first theory of what atoms looked like. -
Solid Sphere Theory
English chemist John Dalton conducted experiments and discovered that everything is made out of atoms in the early 1800's. He created the Solid Sphere theory where he said all atoms are the same and undivisible. -
Plum Pudding Model
English Physicist J.J. Thomson discovered the electron and came up with a model for atomic structure called the Plum Pudding model. He also thought matter had to be positive too, but didn't find anything. -
Discover Photons
Albert Einstein discovered photons and found that atoms emit and absorb light photons. -
Found Charge Of Electrons
Robert Millikan did the famous Oil Drop experiment and found the charge of electrons. -
Nuclear Model
Ernest Rutherford did many tests and discovered that the nucleus of an atom is positive and found and named protons. He created a model of an atom called the Nuclear Model and eventually was questioned. -
Theory Of Atom With Electrons In Orbit
Neils Bohr came up with a theory of an atom called the Planetary Model that said electrons do not float into the nucleus, but rotate in orbits around the nucleus -
Theory Of Electrons
Wolfgang Pauli found that electrons can orbit in either direction and that one electron can be the only one with a certain number of quantum numbers -
Particle Wave Pattern
Louis de Broglie found that atom particles can act like waves. -
PSI Symbol Created And Theory That Vibrations Traveled In Circles
Erwin Schrödinger created a theory that wave vibrations moved in circles in atoms and created the "psi" symbol. -
Quantum Theory, Current Atomic Model
Werner Heisenberg helped create the quantum theory in the 1920's. He is given the credit for the current atomic model. -
Discovery Of The Neutron
James Chadwick discovered the neutron in 1932 and posted his findings and won a Nobel Prize in physics.
