The History of the Atom

  • Democritus
    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

    Dalton

    All matter is composed of very small things that he called atoms. All matter is made up of individual things in 1801.
  • Thomsom

    Thomsom

    Credited for the discovery of the electron. He experimented by doing a charge-to-mass ratio experiment in 1897.
  • Rutherford

    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

    Bohr

    Makes the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus.