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400 BCE
democritus
Democritus thought that atoms were uniform, indestructible, and solid, and they moved infinitely until space stopped. he thought this because if you cut something in half over and over, it would eventually not be able to get any smaller. the piece that you can no longer divide is a single atom. -
John Dalton
Dalton created the four concrete theories about atoms which is that all matter is composed of atoms, atoms of one element are all the same, one atom cannot become a different atom, and all atoms react in whole numbers. -
E. Goldstein
Goldstein suggested the presence of a positively charged particle. He did this by using a tube filled with hydrogen gas and noticed a charge equal and opposite of the electron charge. -
J.J. Thompson
Thompson used the Cathode ray tube to come to the conclusion that there are "bodies much smaller than atoms" inside of atoms. his model is now known as the plum pudding model. -
Robert Millikan
Millikan discovered that there was a fundamental charge in the electrons of an atom. He did this by measuring the movement of oil drops. -
earnest rutherford
Earnest Rutherford discovered that an atom was not just one solid ball, but was mostly empty space with most of its mass in the nucleus. this discovery got little attention until a psychist Neils Bohr showed the importance of it. -
Neils Bohr
After studying Rutherfords model, Bohr came to the conclusion that the inconsistent placing of the electron would cause the atom to be unstable. Working in Rutherfords laboratory, he came to the conclusion that the electrons would occupy specific orbits around the nucleus. -
Erwin Schrodinger
Schrodinger used bohrs model of the atom in order to figure out where the electrons would end up inside of the atom. The model is known as the quantum mechanical model of an atom.
