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470 BCE
Democritus
470 - 380BC, He developed the concept of an atom. He believed everything was made up of atoms. He got a simple seashell and broke it in half. He took that half and broke it in half multiple times until he was finally got a fine powder. He then took the smallest piece from the powder and tried to break it but couldn’t. -
Dalton
All matter is composed of very small things that he called atoms. All matter is made up of individual things in 1801. -
Thomsom
Credited for the discovery of the electron. He experimented by doing a charge-to-mass ratio experiment in 1897. -
Rutherford
Discovered the Rutherford model, discovering that Thompson’s atom was incorrect. This was done in 1909, and many experiments were conducted to get this theory. -
Bohr
Makes the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus.
