Grade: 10th/11th grade chemistry

Time Frame: One week (Invitation-1 day; Internet Research-1 day; Presentations-1 day; Scientist biographies and presentations-1-2 days)

Goal: To shape students knowledge of atomic structure by tracing historical experiments and changes in atomic theory

Overview: Students will express their current knowledge of atomic structure. Groups of students will then use the internet to learn about different models of the atom, from the Greeks to the wave mechanical model. Each group will present their findings to the class.

Materials: Plain paper, drawing materials, one computer for each group connected to the internet, OR with sites downloaded on SiteSnagger for atomic theory research.

Invitation:

1. What do atoms look like? Consult with your group and draw a picture of one.
2. What are the components of atoms? Consult with your group and write down as much as you know about them.
3. How do we know this information about atoms? How do we study atomic structure when atoms are too small to see?  

Exploration:

Since atoms can't be seen, scientists at different times have proposed models of the atom that corresponded to the most recent experimental data. As new experiments were performed, scientists changed their beliefs about the structure of atoms. Each

group will study one of the following models:

1. The Greek concept of the atom

2. Dalton's atomic theory

3. J.J. Thomson's plum pudding model

4. Rutherford's gold foil experiment

5. The Bohr model

6. The wave (quantum mechanical) model

Use any of the following internet sites for information:

ATOMS (A short history of the knowledge of the atom) Compiled by Jim Walker: http://www.sd01.k12.id.us/schools/borah/teachers/purdy/chemweb/atomic/walker/atom.htm

Atomic Structure Timeline: http://www.watertown.k12.wi.us/hs/teachers/buescher/atomtime.html

The Atomic Model: http://pc65.frontier.osrhe.edu/hs/science/pmodel.htm

The Greek Concept of Atomos: The Indivisible Atom: http://dbhs.wvusd.k12.ca.us/Greeks.html

J.J Thomson and Discovery of the Electron: http://dbhs.wvusd.k12.ca.us/Disc-of-Electron-Intro.html

Rutherford's Experiment (more detailed, yet understandable, explanation): http://www.accessexcellence.org/AE/AEC/CC/historical_background.html

picture: http://sal.usask.ca/physics/rutherford.html

The Bohr Model: http://csep10.phys.utk.edu/astr162/lect/light/bohr.html

Modern Theory of Atomic Structure (Quantum Mechanics): http://spaceboy.nasda.go.jp/note/Kagaku/E/Kag02_e.html

http://www.encyclopedia.com/printable/10682.html

http://www.chem.uidaho.edu/~honors/schrod.html

http://www.bcpl.lib.md.us/~kdrews/modern.html

Explanation:

Groups will prepare a 3-5 minute presentation to explain what they learned about their model to the class. Each group should present basic information about the scientist(s) involved in the model's discovery/formation, experiment(s) that lead to the model, and a description of the model itself.

Take Action:

Select one of the scientists mentioned and do an in-depth biography. Include information about their childhood, education, and any other interesting information you can find about them. Stay away from material we have already covered and concentrate on finding out personal information about the scientist. You may want to look at the following Internet sites:

Nobel Prize Internet Archive: http://nobelprizes.com/nobel/nobel.html (Don't forget to look under physics as well as chemistry!)

Cosmology and Cosmologists: http://spaceboy.nasda.go.jp/note/Kagaku/E/Kag_e.html

Index of Biographies: http://www-groups.dcs.st-and.ac.uk/history/BiogIndex.html