2. The Historical View of Atomic Structure Continued

3. What is an Atom?  The smallest particle of an element that retains the properties of the element.

4. Dalton’s Billiard Ball Model

5. Dalton’s Five Part Model  Elements are made of extremely small particles called atoms.  Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.  Atoms cannot be subdivided, created, or destroyed.  Atoms of different elements combine in simple whole-number ratios to form chemical compounds.  In chemical reactions, atoms are combined, separated, or rearranged.

6. J.J. Thompson  Late 1890’s Plum Pudding Model  Contribution: Atoms are divisible (a negative charge exists)  Evidence/Method: Cathode ray tube experiments http://www.youtube.com/watch?feature=playe r_embedded&v=XU8nMKkzbT8

8. J. J. Thompson's Atomic Model

9. Robert Millikan  1909  Contribution: Accurate charge of an electron  Evidence/Method: Oil drop experiment  http://www.kentchemistry.com/links/Ato micStructure/Millikan.htm http://www.kentchemistry.com/links/Ato micStructure/Millikan.htm

10. Ernest Rutherford  1911  Contribution: Atoms are mostly empty space with a central positive mass he called the nucleus  Evidence/Method: Gold foil experiment  http://www.kentchemistry.com/links/At omicStructure/RutherfordTutorial.htm http://www.kentchemistry.com/links/At omicStructure/RutherfordTutorial.htm

11. Rutherford’s Atomic Model

12. James Chadwick  1932  Contribution: Discovered the neutron, the neutral particle in the nucleus of the atom,  Evidence/Method: He did this by bombarding atom’s nuclei with alpha particles. In doing this he could study the structure of the atoms nucleus.  http://www.kentchemistry.com/links/Atomic Structure/Chadwick.htm http://www.kentchemistry.com/links/Atomic Structure/Chadwick.htm

13. Chadwick’s Atomic Model

14. Acknowledgements o Image Source Page: o http://www.squidoo.com/chemistry-lapbook http://www.squidoo.com/chemistry-lapbook  John Dalton’s Atomic Model  http://lindseylester.wordpress.com/science-courses/science- 10/unit-a/lesson-2-atomic-theory/ http://lindseylester.wordpress.com/science-courses/science- 10/unit-a/lesson-2-atomic-theory/  J. J. Thompson’s Atomic Model  http://reichchemistry.wikispaces.com/1875AD-1900AD http://reichchemistry.wikispaces.com/1875AD-1900AD  Chadwick’s Atomic Model  http://reich-chemistry.wikispaces.com/mcgilvray-munsey http://reich-chemistry.wikispaces.com/mcgilvray-munsey