1. History of the Development of the Modern Model of the Atom

2. Dalton’s Atomic Theory (early 1800’s)

3. What did Dalton think the atom looked like?

4. Dalton was not quite correct.

5. Thomson and the Cathode Ray Tube (late 1800’s)
Thomson concluded that the atom was made of ____________________.
Discovered particles with __________
__________________
No matter what metals were used they all produced a negative beam of light
Therefore ____________________________ _____________________________________

6. Thomson theorized a new model of the atom.

7. Rutherford’s Gold Foil Experiment

9. OBSERVATIONS
CONCLUSIONS

10. Rutherford’s Model
Electrons randomly orbit a large, positive nucleus

11. Bohr Model of the Atom (early 1900’s)
Electrons have __________ ______________orbits
Electrons have a _____________
orbits farther from the nucleus have greater energy

12. Electron-cloud model Modern Model
electrons are most likely found in
regions outside the nucleus called _________
and do _______ ______________________ ________________________________

13. orbital shapes

14. THE END