2. Whos right? A metal is always charged because its free electrons can run around If you put a positively charged rod near the wires their positive charges will be pushed away from the rod In a metal both the positive and the negative charges will move If you put a positively charged rod near the wires their free electrons will move towards the rod

3. Measuring electrostatic charges Gold leaf electroscope Charging an electroscope

4. The gold leaf electroscope Acetate rod Gold leaves Copper wire Metal plate The charged acetate rod is too far, so the electroscope is uncharged Click to see animation

6. The gold leaf electroscope Acetate rod Gold leaves Copper wire Metal plate The charged acetate rod is close to the metal plate, so the electrons move to the metal plate and the gold leaves repel each other because full of positive charges. The electroscope is charged by induction.

7. Charging an electroscope Explain in detail what is happening in these situations. Remember… opposite charges attract and like charges repel the charges distribute around the surface of a metal Only electrons (negative charges) are free to move, never positive charges the effects of a negative and a positive charge close together cancel out (neutral) Charged metal ball Insulating handle Click to see animation

9. Draw the position of the gold leaves and the distribution of charges in the following situations.