Inquiry in the Natural World

Student Guide, Topic 7: What is Light? What are Electrons?

Spring 2003

 

Topic objectives

  1.  Be able to identify the major contributions of each of the following scientists: Young, Einstein, Bohr, DeBroglie, Schrodinger, Heisenberg, Davisson, Germer
  2. Appreciate how scientific theories in one area of science (e.g. Physics) can influence developments in another area of science (e.g. Chemistry).
  3. Understand the nature of waves and particles, and the dual nature of light and electrons.
  4. Understand the Bohr model of the hydrogen atom and how it differs from the classical view of matter.
  5. Understand DeBroglie’s matter waves and when such waves are measurable.
  6. Understand Heisenberg’s uncertainty principle and how it limits our knowledge of electrons in atoms.

 

Friday’s Reading Assignment

 

·        Trefil and Hazen , The Sciences, 3rd edition, Chapter 6, pp 125-148 and Chapter 8, pages 178-190.

 

Friday’s Active Learning Exercise

 

·        In the Bohr model, what does it mean to say that the energy of the electron is quantized? Are energy changes also quantized?

·        How do sound waves differ from radio waves?  In what ways are they similar?  Why would x-rays be used in medical diagnosis?

·        How is the movement of the electron around the nucleus in the hydrogen atom different from the movement of the Earth around the Sun in our solar system?

·        Is it possible to make a scientific measurement without disturbing the object measured? When is this consideration important?

 

 

Reading for Monday 3/10/03

Excerpt on Quantum Mechanics from Dr. D. Slaven, Saginaw Valley State University.

http://web.sbu.edu/physics/faculty/dimattio/Clare102/physics.dimattio-sp03.htm

 

Questions for discussion:

 

·        What properties of electrons are particle-like?  Which are wave-like?

·         Describe the double slit experiment with electrons and how it illustrates the wave nature of electrons.

·        What happens to light that is absorbed by matter?

·        Briefly discuss what the Copenhagen Interpretation means.