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460 BCE
Democritus atom
Democritus made the first model of an atom and it looked like a plain sphere. Democritus often referred to the atom as indestructible or indivisible. -
John Dalton
He said all elements are composed of Atoms, atoms of the same element are identical, atoms of different elements combine in simple whole numbers, and in chemical reactions, atoms are combined, separated or rearranged but never changed. -
Dmitri Mendeleev
He created the first far sighted periodic table, and he the periodic law. -
Eugen Goldstein
He is sometimes credited with the discovery of the proton. He is mainly known for the work he did with cathode rays. -
Max Planck
He could describe the behavior of an atom at the atomic level. -
Robert Millikan
He discovered the electron in an atom through the oil drop experiment. -
Niels Bohr
He said that electrons move around the nucleus but only in prescribed orbits -
Erwin Schrodinger
He created the discovered the first way to look at the electrons of the atom through the electron cloud model. -
Werner Heisenberg
He said that a particle's position and momentum cannot both be known at the same time. -
J.J. Thomson's plum pudding model
J.J. Thompson discovered the electron in 1897 and then created the plum pudding model which demonstrated as if the electrons were inside the atom. -
Ernest Rutherford Atom Model
Ernest Rutherford concluded that J.J. Thomson's model was incorrect and that the electrons surrounded what would be the nucleus of the atom. -
James Chadwick
Found that the neutron is found in the nucleus with the proton. The neutron is the same mass as the proton.
