Chemistry 241-2007

Exam #1 Practice Questions

1. Calculate the effective nuclear charges for B and F. Explain the relative sizes of B and F, in light of your calculated Z* values.

2. Calculate the effective nuclear charges for Li and Na. Explain the relative sizes of Li and Na, in light of your calculated Z* values.

3. Describe and explain the general trend in atom size moving across and down the periodic table.

4. Why do zeolites that contain Al absorb water better than those that do not?

5. Explain how you would make a silicone rubber that was very flexible.

6. a. Explain why diamond does not spontaneously turn into graphite. Explain why graphite does not spontaneously turn into diamond.

b. Examine your copy of the phase diagram for carbon. In which regions is a species metastable. Explain the choices.

7. Draw the band structure for a:

conductor

intrinsic semiconductor

insulator

8. Draw a band structure for p- and n- type Si-based semiconductors. Explain why they are called (n vs. p) what they are.

9. What is the limiting factor in creating computer chips with ever more circuits per square centimeter?

10. Explain the preferred structures of the elements S and O in terms of enthalpy and entropy.