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Democritus
Democritus suggested the first atomic theory, explaining that all things are "composed of minute, invisible, indestructible particles of pure matter which move about eternally in infinite empty." -
John Dalton
He made inferences in the 19th century that exhibited how atoms bond together in definite proportions -
J.J. Thomson
He was credited for discovering the electron, ended up contributing to more than the atomic theory. -
Earnest Rutherford
He discovered the proton using the "gold foil" experiment and that atoms are composed of mostly empty space. -
Niels Bohr
He made the "Bohr Theory of the Atom". This theory was the closest to the modern atomic theory re-emphasized the idea of electrons around the nucleus. Bohr suggested that electrons orbited around the nucleus in seven different quantum levels, or shells. -
Murray Gell
United States physicist, noted for his classification of subatomic particles and his proposal of the existence of quarks.
