Chapter 5

1. Why do astronauts on the moon have to communicate by radio even when close to one another?
2. Explain why sounds travel faster in warm air than in cool air.
3. What are the significant similarities and differences between longitudinal and transverse waves? Give examples of each.

Chapter 6

1. What is the difference between AC and DC?
2. What is a magnetic pole? How are magnetic poles named?
3. What are the basic similarities and differences between an electric field and a magnetic field?

Chapter 8

1. What does atomic number mean? How does the atomic number identify the atoms of a particular element? How is the atomic number related to the number of electrons in an atom?
2. Describe the three main points in the Bohr model of the atom.
3. What are the significant similarities and differences between the isotopes of a particular element?

Chapter 11

1. Describe three kinds of radiation emitted by radioactive materials. Describe what eventually happens to each kind of radiation after it is emitted.
2. What is meant by background radiation? What is the normal radiation dose for the average person from background radiation?
3. Why is there controversy about the effects of long-term, low levels of radiation exposure?