Combining Atoms

• Provided a more precise description of the atom in Dalton's Atomic Theory


  John Dalton
• Elements are made up of extremely small particles called atoms
• All atoms of a certain element are exactly alike. Atoms of different elements are different
• Atoms of same elements have the same

  sizes, mass and chemical properties
• Atoms of one element combine with atoms of another element to form compounds
• A chemical reaction does not result in the creation or destruction of atoms
• A chemical reaction results only in the separation, combination, or rearrangement of atoms
• It is the model of the atom

  Solid Sphere Model
• Laws based on Dalton's Atomic Theory

  Law of chemical combination
• Mass can neither be created nor destroyed in a chemical reaction

  Law of Conservation of Mass
• A pure compound will always have the same proportion if the same elements

  Law of Constant (Definite) Proportions