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465 BCE
Democritus
He created the first model of the atom. He gave the idea that atoms are indestructible. -
Period: 465 BCE to
The Timeline
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335 BCE
Aristotle
Didn't believe in the Atomic theory. He believed that everything in the world was made up of the elements of matter, Earth, Air, Fire and/or Water. -
Antoine Lavoisier
He was the first to wonder what actually an atom would look like. He also made the Law of Conservation of Mass- Matter cannot be created nor destroyed. -
Joseph Louis Proust
He proposed the Law of Definite Proportions where is says the ratio of elements in a compound is always the same/constant. -
John Dalton
Evolved the theory to say that Atoms are spherical based on the properties of Mass that was measurable at the time. -
J.J. Thompson
he found out that electrons have negative charges with the positive ones and it comes from ordinary matter. He made the Plum Pudding Model of the Atom. -
Earnest Rutherford
He conducted an experiment where she shot alpha particles through a thin foil of gold to see what angles the beams would have.He made the Nuclear Model of an Atom. -
Niels Bohr
He added to the model of the atom after discovering that they're surrounded by orbital electron shells. He made the Planetary Model of an Atom. -
James Chadwick
He found a neutral atomic particle in an atom that had a similar mass to a proton. He would call this the neutron. -
Erwin Schrodinger
He gave the theory that was later proven correct that electrons are constantly moving all around the atom and don't have one set position or motion. He would make the Quantum Mechanical Model of an Atom. -
Werner Heisenber.
Discovered that electrons in the atom will change the momentum and physics of an object. -
Murray Gell-Mann
He discovered the up and down quarks in the atom. An up quark has a positive charge of 2/3 while the down quark has a negative charge of 1/3.