1. Democritus -Greek philosopher 450 BC

2. Aristotle -born 384 BC -Greek philosopher, educator & scientist -student of plato

3. Lavoisier -French chemist 1700’s -“Law of Conservation of Mass”

4. 2 Mg + O 2 2 MgO 10.0g 6.58g 16.58g

5. Joseph Proust -1754-1826 -French Chemist -Law of Definite Proportions H20H20 Looking at …

6. JohnDalton -English school teacher & scientist -Early 1800’s -Atomic Theory of Matter -Law of Multiple Proportions

7. Dalton’s Periodic Chart

8. Dalton’s Model of an Atom

9. William Crookes -1832-1919 -English Chemist -developed the cathode ray tube

10. Cathode Ray Tube in Action Cathode Ray Tubes

12. Michael Faraday -1791-1867 -English chemist and Physicist -Electromagnetic induction Induction

13. Ben Franklin -1706-1790 -scientist, inventor, statesman -looked at electrical charges

14. Chadwick -studied alpha particles to discover neutrons

15. -English physicist early 1900’s -Worked with cathode ray tubes JJ Thomson

16. Electron Beam in CRT

17. + - + + + + + + - - - - - Plum Pudding Model

18. Ernest Rutherford -New Zealand Scientist early 1900’s -Alpha scattering experiment

20. 98% of the particles passes straight through 2% of the particles deflected off at varying angles 0.01% of the particles bounced straight back

21. + - + + ++ ++ - - - - - Rutherford’s Model of an atom

22. Max Planck -German Physicist -1858-1947 -studied light emitted from objects

23. E = h v Planck’s Theory … What does it mean?

24. Photoelectric Effect

25. Albert Einstein -1879-1955

26. Niels Bohr -Danish physicist early 1900’s -Used Rutherford’s planetary idea -Used Plank’s idea of “quanta”

27. Planetary model of an atom

28. Robert Millikan -1868-1953 -American physicist

29. Milikan’s Oil Drop Experiment On-line Model

30. Werner Heisenberg -1901-1976 -Uncertainty Principle

31. Erwin Schrodinger What’s that? Sign your planner? We’re talking quantum mechanics here folks …

32. Schrodinger wave model of an atom orbitron

33. Henri Becquerel Marie and Pierre Curie

34. Henry Moseley -1887-1915 -Rutherford’s student