1. [http://www.nist.gov/public_affairs/images/04PHY014_HipHopAtomSurfc_HR.jpg]

2. Democritus (450 BC) Everything is made up of small particles called “atomos”. These particles were indivisible. [http://faculty.washington.edu/smcohen/320/Democritus.jpg]

3. Dalton’s Atomic Theory (1807) Elements are composed of atoms. Atoms of a specific element are identical. [http://www.kjemi.uio.no/software/dalton/graphics/john_dalton.gif]

4. Dalton’s Atomic Theory (1807) Atoms are not created or destroyed in reactions. A compound always has the same combination of atoms [http://wps.prenhall.com/wps/media/objects/602/616516/Media_Assets/Chapter02/Text_Images/FG02_02.JPG]

5. The Electron Benjamin Franklin (mid-1700’s) (+) and (-) charges exist. Did not know where they came from. [http://www.npl.co.uk/publications/electricity/images/kite.gif]

6. The Electron Cathode Ray Tube or CRT (mid-1800’s) “Beam” traveled from positive to negative end of tube. [http://members.chello.nl/~h.dijkstra19/image/burning%20ray%20tube.jpg] Click Here for a CRT Video

7. [http://wps.prenhall.com/wps/media/objects/602/616516/Media_Assets/Chapter02/Text_Images/FG02_03.JPG]

8. [http://www.cheniere.org/images/Magnet%20on%20TV.jpg]

9. The Electron Thompson’s “Plum Pudding Model” (1896) Light is not moved by a magnet, so the “light” in the CRT must be charged particles in atoms.

10. Radioactive Particles Becquerel & Curie (1896) Certain elements emit both negative and positive particles

11. Radioactive Particles Rutherford’s Gold Foil Experiment. Shot radioactive particles at a thin piece of gold.

12. Click here for video of actual results

13. Radioactive Particles Rutherford concluded that all the positive charges of an atom would be contained in the middle or nucleus.