1. At some automobile toll-collecting stations, a thin metal wire sticks up from the road and makes contact with cars before they reach the toll collector. What is the purpose of this wire?

Question

2. The leaves of a charged electroscope collapse in time. At higher altitudes they collapse more rapidly. Why is this true? (Hint: The existence of cosmic rays was first indicated by this observation.)
3. In a crystal of salt are electrons and positive ions. How does the net charge of the electrons compare with the net charge of the ions? Explain.
4. It is relatively easy to strip the outer electrons from a heavy atom like that of uranium (which then becomes a uranium ion) but very difficult to remove the inner electrons. Why do you suppose this is so?

Answer 1

The electric force is stronger when the electron is closer to the nucleus