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400 BCE
Democritus
came up with the theory of atomism, that all matter is made up of tiny particles -
John Dalton
Theory that an element is composed of only one kind of atom, and a compound is composed of particles that are chemical combinations of different kinds of atoms -
Dmitri Mendeleev
published the Periodic Table -
Eugene Goldstein
discovered protons while experimenting with cathode -
JJ thomson
Examined two ways that a cathode ray can be deflected, using a magnet and using electrically charged plates -
Ernest Rutherford
first to discover that atoms have a small charged nucleus -
Niels Bohr
First to discover that electrons travel in seperate orbits -
Robert Millikan
Carried out experiments to find the quantity of charge carried by an electron, using charge to mass ratio of an electron measured by thomson -
Max Planck
He originated quantum theory, he won a Nobel prize for physics -
Werner Heisenberg
known for his uncertainty principle and theory of quantum mechanics -
Erwin Schrodinger
Took the Bohr atom model one step further, used mathematical equation to find an electron in a certain position -
James Chadwick
He discovered the Neutron, he was awarded the Nobel Prize
