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460 BCE
Democritus
Democritus was the first to suggest that all matter consisted of small indivisible particles -
John Dalton
John Dalton was the first to state that all matter is made of atoms and they are indivisible and indestructible. -
Max Planck
Max Planck first discovered quantum theory which is a theory of matter and energy based on the concept of quantum -
Dmitri Mendeleev
Dmitri Mendeleev is the man who discovered and made the periodic table -
Eugene Goldstein
Eugene Goldstein discovered protons He discovered protons with the experiments he did with cathode rays which would knock electrons of atoms and attract them to a positively charged electrode. -
J.J. Thomson
J.J. Thomson discovered the electron by experimenting with a Crookes. The model that he drew was known as the plum pudding model -
Ernest Rutherford
Ernest Rutherford was the person to first discover the nucleus by doing the "scatter" experiment -
Niels Bohr
Niels Bohr was the first to suggest that electrons have separate orbit routes around the nucleus and that the number of electrons around it determined the properties of the elements -
Robert Millikan
Robert Millikan did the "oil drop" experiment He determined that there was a smallest 'unit' charge, or that charge is quantized -
Werner Heisenberg
Werner Heisenberg created the theory of quantum mechanics. THis resulted in the discovery of allotropic forms of hydrogen -
Erwin Schrodinger
Erwin Schrodinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This became known as quantum mechanical model of the atom -
James Chadwick
James Chadwick discovered the neutron, it was a uncharged but massive particle. It could be used to probe other nuclei.
