1. Electroscopes

2. Essential Questions for the Electroscopes Lesson:
How do charges behave when they are under the influence of a charged rod?
What are the parts of an electroscope?
How does an electroscope operate?
What is another name for charge shift?
What is the difference between a charge shift and a charge transfer?
What is the difference between charging by induction & charging by conduction?
How is an electroscope charged by induction?

3. Neutral objects are attracted to charged objects...- +
Electrons shift...

4. Neutral objects are attracted to charged objects...+ -
Electrons shift because...
Opposite charges attract.

5. Neutral objects are attracted to charged objects...- +
Electrons shift because...
Opposite charges attract.

6. Neutral objects are attracted to charged objects...- +
Electrons shift because...
Opposite charges attract.

7. Neutral objects are attracted to charged objects...+ -
Electrons shift because...
Opposite charges attract.

8. The object is now polarized with charge.+ -

9. Dial Electroscope
Uncharged
Charged

10. Leaf Electroscope
Uncharged
Charged

11. INDUCTION
Neutral Electroscope

12. INDUCTION Electrons shift toward the positively charged object... e- e- e-
Electrons shift toward the positively charged object...

13. INDUCTION - + +
Charged Electroscope

14. Neutral Electroscope

15. INDUCTION
Neutral Electroscope

16. INDUCTION Electrons shift away from the negatively charged object... e- e-
Electrons shift away from the negatively charged object...

17. INDUCTION + - -
Charged Electroscope

18. Neutral Electroscope

19. CONDUCTION e- e- Electrons transfer on the electroscope... e- e-

20. - - - CONDUCTION Electrons transfer on the electroscope... -
Placing a residual charge on the electroscope... - -

21. Negatively Charged Electroscope- - -

22. CONDUCTION e- e- Electrons transfer out of the electroscope... e- e-

23. + + + CONDUCTION Electrons transfer out of the electroscope... +
Placing a residual charge on the electroscope... + +

24. Positively Charged Electroscope+ + +

25. RESIDUAL CHARGE BY INDUCTION

26. RESIDUAL CHARGE BY INDUCTION - + +
First, electrons shift ...

27. RESIDUAL CHARGE BY INDUCTION - + +
Second, with the charged rod still nearby, the electroscope is grounded ...

28. RESIDUAL CHARGE BY INDUCTION e- - + +
allowing electrons to enter (transfer in) ...

29. RESIDUAL CHARGE BY INDUCTION e- - e- + +
and move toward the positive leaves.

30. RESIDUAL CHARGE BY INDUCTION e- - e- + +
Now the electroscope has excess electrons ...

31. RESIDUAL CHARGE BY INDUCTION- - -
and is negatively charged.

32. Using a negatively charged rod near the electroscope and grounding the electroscope results in...
A positive residual charge.

33. Check Questions for the Electroscopes Lesson:
How do charges behave when they are under the influence of a charged rod?
What are the parts of an electroscope?
How does an electroscope operate?
What is another name to describe charge shift?
What is the difference between a charge shift and a charge transfer?
What is the difference between charging by induction & charging by conduction?
How is an electroscope charged by induction?

34. You have completed the Electroscopes Lesson.
Captain Einstein says “Good Job!”