2. Atom Model History Where did it all begin?

3. What is an atom? The smallest particle of an element that can keep the same properties of the element. What is the smallest number of carbon atoms that have all of the properties of carbon? One

4. Democritus (Ancient Greece, 440 B.C.) He stated that atoms are the smallest particles of all matter. Democritus Who was the first person to use the word atom?

5. Dalton (1803) He proposed that atoms: –are the smallest part of matter. –cannot be created, divided, or destroyed. –of the same element are alike. (H = H) –of different elements are different. (H is not O.) –join to make new substances. (H + H + O = H20) No, he proposed (suggested) them. Did Dalton discover all five of these ideas?

6. Thomson (1897) Discovered electrons “Plum Pudding” Model: atom is a lump of positively charged matter with electrons scattered throughout (like chocolate chip cookie dough.) Did JJ Thompson discover protons? No, he just suggested positive matter.

7. Rutherford (1902) Discovered atoms have a nucleus (small, dense, positively-charged center) Atoms are mostly empty space Solar System Model How is this model like a solar system? It has objects (electrons) moving around a central point (nucleus).

8. Bohr (1913) Said electrons move around the nucleus at certain speeds. Did Mr. Bohr know that electrons moved? How? Yes, because of Rutherford’s research.

9. Schrodinger (1920’s) Said electrons are in “clouds” around the proton- and neutron- filled nucleus. Said the “clouds” have different amounts of energy. What is Schrodinger’s first name? Erwin

10. Heisenburg 1927 Said where the electron clouds could exist in the atom. Argued a lot with Schrodinger.. Was Heisenburg a student of electrons? Yes he was.

11. Helpful Websites http://www.broadeducation.com/htmlDemo s/AbsorbChem/HistoryAtom/page.htmhttp://www.broadeducation.com/htmlDemo s/AbsorbChem/HistoryAtom/page.htm http://www.csmate.colostate.edu/cltw/coho rtpages/viney/atomhistory.htmlhttp://www.csmate.colostate.edu/cltw/coho rtpages/viney/atomhistory.html http://www.nobeliefs.com/atom.htm

12. Lab Outline http://www.integratelearning.org/Lesson% 20Bank/AMcGinley/lp1pp1_files/frame.htmhttp://www.integratelearning.org/Lesson% 20Bank/AMcGinley/lp1pp1_files/frame.htm