1. All matter contains both positively and negatively charged particles. Why do most things have no net charge?

3. What is a positive ion? A negative ion?

5. Describe the similarities and the differences between the gravitational force between two objects and the electrostatic force between two charged objects.

7. In otherwise empty space, what would happen if the size of the electrostatic force acting between two positively charged objects was exactly the same as that of the gravitational force acting between them? What would happen if they were moved closer together or farther apart?

9. What is an electric field? Sketch the shape of the electric field around a single proton.

11. Explain what an electrostatic precipitator is and how it works.

13. Saltwater contains an equal number of positive and negative ions. When saltwater is flowing through a pipe, does it constitute an electric current?

15. A solid metal cylinder has a certain resistance. It is then heated and carefully stretched to form a longer, thinner cylinder. After it cools, will its resistance be the same as, greater than, or less than what it was before? Explain your choice.

17. If a new material is found that is a superconductor at all temperatures, what parts of some common electric devices would definitely not be made out of it? Explain.

19. Make a sketch of a simple electric circuit and label the key elements in the circuit.