History of the Development of the Modern Model of the Atom

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 modelModern Model electrons are most likely found in regions outside the nucleus called _________ and do _______ ______________________ ________________________________

13. orbital shapes

14. THE END