Questions for Focused Reading

The nature of matter

12.1

1.    What is the relationship between wavelength and frequency?

12.2

2.    Describe the prevailing beliefs about matter and energy at the end of the 19th century.

3.    What is  the ultraviolet catastrophe?  For what type of matter does it occur?

4.    What assumption of classical physics did Planck ignore?

5.    What is the relationship between energy, frequency, and wavelength?

6.    Einstein studied Planck's work and concluded that if energy were quantized, then it follows that energy is particulate.  What are these particles called and who named them?

7.    What was de Broglie's contribution to the dual nature of matter?  Restate the equation in English.

8.    Finish the following sentences:  Diffraction can only be explained in terms of ______________.  Electrons can be diffracted, therefore, electrons must be ____________.

12.5

9.    Define the pieces of the Schrodinger equation.

10.    What do an orbit and an orbital have in common?

11.    Your textbook very clearly states that an orbital is not an orbit, and that the electron does not zoom around the nucleus on an orbit like a race car on a three-dimensional race-track.  Then it asks a very important question.  "How. . . is the electron moving?"  Your textbook says we do not know the answer.  I disagree.  I say that it is an irrelevant question.  Consider this.  How does a standing wave move?  Certainly, that is an irrelevant question.  We don't consider how a standing wave moves because it is a wave.  It exists in its allowed region of space.  Likewise, it is not relevant to consider how an electron moves.  It exists in its allowed region of space.  Yet, an electron is a particle.  We know it is because it has mass!  So, is it accurate to say that an electron jumps back and forth from particle to wave?  No.  An electron is an electron.  It always has both particle and wave nature.  What jumps back and forth is the way our brains deal with the information about an electron.  We treat electrons like waves when the wave part of their nature is important for solving a problem.  We treat electrons like particles when the particle part of their nature is important.  If you are not confused by the dual nature of matter, then you are not thinking hard enough.

12.7

12.    There are several solutions to the Schrodinger equation.  Several wave functions are  listed for a one-electron atom in Table 12.1.  In order to come up with these functions, it is necessary to define three quantum numbers.  What are their symbols and what are they called?

12.8

13.    What is the significance of the square of the wave function?

14.    What is the difference between Figure 12.16 and 12.17?  Which is more useful?

15.    What is the significance of 90% of the total electron probability?