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Atomic theory (Democritus (Greek philosopher (Let final particle called…
Atomic theory
Democritus
Greek philosopher
Let final particle called Atom
Atom mean invisible in Greek
Atom have different size and shape
Atoms are indestructible and indivisible
John Dalton
The first to use experimental data to support the existence of atoms
He create atomic theory called Dalton's atomic theory
All matter made up of atom
Atom can't be created, destroyed, or subdivided
Atom of differ elements have differ size, mass, and other properties.
Atoms of different elements can be chemically combined
In chemical reactions, atoms are combined, separated and rearranged.
JJ Thomson
English physicist
Made cathode ray tube (CRT)
Cathode ray always attracted to positive charge
Plum pudding model
Negatively charged particles held inside a positively charge sphere.
Ernest Rutherford
Gold foil experiment
Shot alpha particles at a thin sheet gold foil
The result: some alpha particles reflected back
Atom must have a very small but dense and positively in the center called nucleus
Atom is mostly empty space
Aristotle
All elements are made up of 4 elements