1. Electroscopes and Charges

2. Charge Distribution One of these isolated charged spheres is copper and the other is rubber. The diagram below depicts the distribution of - charge over the surface of two spheres. Which one is rubber and which one is copper? Rubber Copper

3. Charge by Conduction Electrons flow from a charged object to an uncharged object through contact.

4. Charging an electroscope by contact - What will happen as a positively charged rod is brought near?

5. Grounding a negatively charged electroscope - Which way will the electrons flow?

6. Grounding a positively charged electroscope - Which way will the electrons flow?

7. Charge by Induction of an Electroscope

8. Charge by Induction Electrons flow from one sphere to the other due to separation of charge.

9. Key Ideas Objects become charged by losing or gaining electrons. –Negatively charged objects have an excess of electrons. –Positively charged objects have a deficiency of electrons. Like charges repel. Unlike charges attract. Conductors allow electrons to flow freely. Insulators do not allow electrons to flow easily. Separation of charge occurs when objects become charged or when a charged object is brought in local proximity to an uncharged (neutral) object.

10. Key Ideas Charge by conduction results when charge is transferred through contact. Charge by induction occurs when a charged object is place in local proximity to a neutral object causing a separation of charge.