History of The Atom

  • Aristotle BC
    345

    Aristotle BC

    +Thought all materials on earth were not made of atoms but the 4 elements
    +
  • Democritus BC
    460

    Democritus BC

    +Developed the idea of atom +Modeled it with a solid ball +Didnt know about a nucleus or electrons, just that everything is made of atoms
  • Dalton

    Dalton

    +Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass
    +Made careful quantitive measurements which allowed the compositions of compounds to be determined w/ accuracy
    +tiny, indestrutive particles & each had a certain mass, size, and chemical behavior that was determined by what kind of element they were
  • Thomson

    Thomson

    J.J Thomson discovered the electron using the cathode tray tube in 1904
    Thomson thought the atoms was a sphere of positive force with eletrons around it.
    a sphere of positive force with electron
  • Rutherford

    Rutherford

    +Descovered the nucleus
    +Theory was that the atom has a positive nucleus w/ negative electrons orbiting around
  • Bohr

    Bohr

    +Created Atomic Model
    +Applied quantum theory to Rutherfords atomic structure w? assuming that electroms travel in stationary orbits defined by their angular momentum
  • Heisenberg and Schrodinger

    Heisenberg and Schrodinger

    • Descovered th "Uncertanty Principle"
    • Caculated the behavior of electrons +Looked like a cloud