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380 BCE
Democritus
He believed that everything in the universe was made up of atoms. -
John Dalton
Developed a crude method for measuring the masses of the elements in a compound. Dalton's Atomic Theory: All elements are composed of atoms. Atoms of the same element are identical. -
Dimitri Mendeleev
He was the one who discovered the periodic table. -
Eugene Goldstein
He discovered protons with the experiments he did with cathode rays -
J.J. Thomson
He was the first person to discover an electron. He used a cathode ray tube. -
Max Planck
Best known as the originator of the quantum theory of energy -
Robert Millikan
Discovered the elementary change of an electron using the oil-drop experiment -
Ernest Rutherford
He was the first person to discover the nucleus. The nucleus is small, the nucleus is dense, the nucleus is positively charged -
Niels Bohr
Niels Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. -
Erwin Schrodinger
Used mathematical equations to describe the likelihood of finding an electron in a certain position. -
James Chadwick
He was the first person to discover the neutron by comparing electric charges and masses of different atoms. The neutron is found in the nucleus with the proton. -
Werner Heisenberg
Was known for his uncertainty principle and theory of quantum mechanics.
