1. Atomic Theory Date

2. Democritus Date 460-370 B.C. Democritus was a philosopher; did no research He thought that everything was made up of tiny round things called atoms. Atoms are the building blocks of life.

3. John Dalton 1787 – 1844 Wanted to learn in what ratios different elements combine in chemical reactions. Through experimentation devised his atomic theory.

4. Dalton’s Atomic Theory 1.Elements are composed of submicroscopic indivisible particles called atoms. 2.All atoms of a given element are identical. Atoms of different elements are different from one another. Now that we know about subatomic particles this point is no longer valid. Now that we know about isotopes, this point is not entirely valid.

5. 3.Atoms of one element can mix or chemically combine with atoms of other elements, creating compounds with simple whole- number ratios. animation of Dalton's 3rd point 4.Chemical reactions occur when atoms are separated, joined or rearrange.

6. Na + OH - H+H+ Cl - Reactants

7. Na + OH - H + Cl - Energy used to break bonds

8. Na + OH - H + Cl - Atoms rearrange

9. Na + OH - H + Cl - Atoms join Technically, not atoms, but ions that join and break apart

10. JJ Thomson Found electron Used cathode ray tube – Beam bent away from negative magnet – cathode ray tube in action cathode ray tube in action “Plum Pudding” or “Chocolate Chip Cookies” model

11. Robert Millikan Determined the electrical charge of electron “Oil Drop Experiment” – Suspended oil in mid-air – Millikan's experiment explained Millikan's experiment explained – What Milikan saw What Milikan saw – Milikan's experiment set to music Milikan's experiment set to music Still plum pudding model

12. Basic sketch of his experiment Still plum pudding model

13. Eugene Goldstein Found the proton Reverse cathode ray tube – Looked at ray going to anode Still plum pudding model

14. Ernest Rutherford Found nucleus The Gold Foil Experiment Atom is mostly empty space – first nuclear model

15. Rutherford Halo Style Bill Nye the atom

16. James Chadwick Found neutron Shot alpha particles at Be nucleus Nucleus is made of two particles – Positive protons – Neutral neutrons

17. Niels Bohr Reasoning for Bohr's model Planetary model Proposed electrons have a set amount of energy putting them in different energy levels, or orbits around the nucleus. Electrons can change energy levels; higher energy levels are further from the nucleus.

18. Heisenberg Heisenberg’s uncertainty principle: cannot know exactly both the velocity and position of electron at the same time. Heisenberg's uncertainty principle explained Heisenberg's uncertainty principle explained Like trying to catch a helium balloon in the dark.

19. Schrödinger Electron cloud gives a 90% probability of finding the electron within the darkly shaded area. Electrons move like moths around a light – unpredictable.

20. example project – rap w/o words example project example 2 – good idea, but do spell check, make sure people can read the words (speed and color) example 2 phenomenal example – this is the ideal project phenomenal example atom rap – no pictures, but at least you can read the words. atom rap