A Timeline about the Atomic Theory

By TaylarG
  • 460

    Democritus

    460 B.C. Democritus discovered the atom. He asked the question: If you break a piece of matter in half, and then break it in half again, how many breaks will you have to make before you can break it no further?
  • Dalton

    Dalton
    Theories: 1) all substances are made of atoms. Atoms of the same element are exactly alike. Atoms of different elements are different
    2) Atoms are small particles that cannot be created
    3) [articles can not be divided, or destroyed
    -join with other atoms to make new substances
    -published atomic theory in 1803
  • Thomson

    Thomson
    Thomson discovered electrons
  • Chadwick

    proves the existence of the neutron in 1932 what accelerated the research in nuclear physics immensly
  • Rutherford

    Rutherford tested and improved Thomson's theory
    -He stated that not all atoms are soft blobs of matter
  • Bohr

    Electrons move around nucleus in certain paths