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340
Aristotle
Aristotle beleived there in an atom there were four elements and four qualities, and that they would be in the same place they began when at rest. -
Period: 340 to
Atomic Theory
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440
Democritus
Democritus believed atoms were hard and small particles followed by one substance and in one shape. He thought they were always moving and combined with each other. -
Robert Boyle
Boyle believed that gasses are made up of tiny particles that group together. -
Antoine Lavoisier
Lavoisier created the idea of having on single -common language for all of science to use. -
John Dalton
Dalton believe that the reason elements combined was because all elements are made up of atoms. -
J.J Thomson
Thomson used a cathode ray tube to discover that there are small particles inside of every atom. -
Hantaro Nagoaka
Nagoaka developed an early but incorrect model of the atom. -
Ernest Rutherford
Rutherford create an expirament, he shot a positively charged beam of particles through a sheet of gold foil. -
Neils Bohr
Bohr suggested that electrons travel around the nucleus in definite paths. -
Quantum Mechanical Model
This is the current day model of an atom and is based on a theory of quantum mechanics. Each electron is a cloud, of negative charge, instead of one tiny negative particle. It is believed in this model that electrons fill all of the space in an atom at different levels.