1. The History of the Atom Democritus to Rutherford

2. Democritus Matter composed of atoms Indivisible No evidence Image creditted to: http://darkwing.uoregon.edu/~ch111/images/democritus.gif

3. John Dalton Matter consists of atoms Atoms cannot be destroyed (indivisible) Atoms of the same element have the same properties Atoms can chemically combine in whole number ratios Subatomic particles http://images.google.com/imgres?imgurl=http://darkwing.uoregon.edu/~ch111/images/democritus.gif&imgrefurl=http://darkwing.uoregon.edu/~ch111/L5.htm&h=225&whttp://images.google.com/imgres?imgurl=http://darkwing.uoregon.edu/~ch111/images/democritus.gif&imgrefurl=http://darkwing.uoregon.edu/~ch111/L5.htm&h=225&w= 150&sz=8&hl=en&start=3&usg=__VrAAh3ZgR8p7vQh46MmBNjIvMsM=&tbnid=BVFhvE_VkFy6ZM:&tbnh=108&tbnw=72&prev=/images% 3Fq%3Ddemocritus%2Batomic%2Bmodel%26gbv%3D2%26hl%3Den%26sa%3DX

4. J.J. Thomson Cathode ray tube Electric current through gas Cathode ray moves toward anode Beam can be deflected fImage credited to: http://nobelprize.org/educational_games/physics/quantised_world/structure-1.html

5. The Thomson Plum-pudding Model The discovery of the electron Image credited to: http://nobelprize.org/educational_games/physics/quantised_world/structure-1.html

6. Ernest Rutherford Gold foil experiment Alpha particles, gold foil, screen Image credited to: http://www.nitrogenorder.org/lessons/nuclear/goldfoil.jpg

7. Rutherford’s Expectations Plum-pudding model Particles will easily pass through with only slight deflection due to positive charge Image credited to: http://content.answers.com/main/content/wp/en/thumb/5/58/200px-Gold_foil_exp_conclusions.jpg

8. Actual Results Most pass through- EMPTY SPACE Positive charge and mass are concentrated Discovery of nucleus Image credited to: http://www.green-planet-solar-energy.com/images/gold_foil_2a.jpg