Evolutions of atomic theories

By lmcruz17
  • 460 BCE

    Democritus

    Democritus
    “Matter as made up of tiny individual particles called atoms. Atoms could not be created, destroyed or further divided.”

  • Dalton

    Dalton
    1. Matter is made up of tiny particles called atoms.
    2. Atoms of a given element are identical in size, mass, and chemical properties. Different from different elements.
    3. Atoms of two or more different elements combine to form compounds.
    4. A chemical reaction involves the rearrangement, separation, or combination of atoms.
      Atoms are never created or destroyed during a chemical reaction.

  • Dalton's Model

    Dalton's Model
    Indivisible and indestructible atoms.
    It helped us to understand that atoms cannot be destroyed or can't be separated.

  • Thompson

    Thompson
    Applied electricity to a glass tube and produced streams of small particles called cathode rays. Then, particles must be negatively charged, they were called electrons. Atoms are neutral; thus, the sphere contains the same quantity of positive and negative charges.

  • Plum Pudding Model

    Plum Pudding Model
    Negative charges over a positive atom.