1. Chapter 11 Question 54: Do radio waves travel at the speed of sound, at the speed of light, or somewhere in between? (0.5 pts)

2. Chapter 11 Question 61: Trucks often have signs on the back that say "if you can't see my mirrors, I can't see you". Explain the physics behind this. (0.5 pts)

3. Chapter 11 Question 71: In a dress shop with only fluorescent lighting, a customer insists on taking items into the daylight to check their color. Is the customer being reasonable? Explain why or why not. (0.5 pts)

4. Chapter 11 Question 85: When you stand with your back to the Sun, you see a rainbow as a circular arc. Could you move off to one side and then see the rainbow as the segment of an ellipse (oval) rather than the segment of a circle? Defend your answer. (0.75 pts)

5. Chapter 12 Question 42: The atoms that compose your body are mostly empty space, and structures, such as the chair you're sitting on are composed of atoms that are also mostly empty space. So why don't you fall through the chair? Hint: Think chemistry, not physics concepts from Chapters 1-4 for this!) (0.5 pts)

6. Chapter 12 Question 50: If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element? (0.5 pts)

7. Chapter 12 Question 54: Explain why the atomic masses listed in the periodic table usually are not whole number. (0.5 pts)

8. Chapter 12 Question 85: Use the shell model to explain why a potassium atom (K), is larger than a sodium atom (Na). (0.5 pts)

9. Chapter 12 Question 76: How can a hydrogen atom, which has only one electron, create so many spectral lines? (0.75 pts)