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460 BCE
In the Beginning
a Greek philosopher, Democritus, develop the idea of atoms. He asked a question that changed how people think. the question was If you break a piece of matter in half, and then break it in half again, how many breaks will you have to make before you can break it no further? -
Solid Sphere Model
an English chemist, John Dalton performed experiments with various chemicals that showed that matter, indeed, seem to consist of elementary lumpy particles (atoms). Although he did not know about their structure, he knew that the evidence pointed to something fundamental. -
The Plum Pudding Model
English physicist J.J. Thomson discovered the electron and proposed a model for the structure of the atom. Thomson knew that electrons had a negative charge and thought that matter must have a positive charge. His model looked like raisins stuck on pudding. -
The Nuclear Model
Ernest Rutherford thought it would prove interesting to bombard atoms with these alpha rays, figuring that this experiment could investigate the inside of the atom (sort of like a probe). -
The Bohr (Planetary) Model
a Danish physicist, Niels Bohr came up with a theory that said the electrons do not spiral into the nucleus and came up with some rules for what does happen. -
Quantum Mechanics Model
the Austrian physicist, Erwin Schrödinger had an idea. HIs idea was why not go all the way with particle waves and try to form a model of the atom on that basis? His theory worked kind of like harmonic theory for a guitar string but the vibrations moved in circles. -
Murray Gell- Mann/ Yuval Ne'man
Murray Gell-Mann and Yuval Ne'man proposed a method for classifying all the particles and made the periodic table The method became known as the Eightfold Way. What the periodic table did for the elements, the Eightfold Way did for the particles.