1. Aim: How can we explain electrostatics? Do Now: Why is it that when you walk on a carpeted surface with socks on, this happens:

2. Electrostatics The study of stationary charged particles

3. Charged Particles Elementary Particles: –Electron (-e)  negative charge –Proton (+e)  positive charge –Neutron  no charge Ion: a charged object that has lost or gained an electron

4. Like Signs 2 like signs experience a force of repulsion

5. Unlike Signs 2 unlike signs experience a force of attraction

6. Neutral Objects Neutral objects are attracted to charged objects Balloon Demo

7. Why does the balloon stick to the wall? Balloon (rubbed over hair) Wall (Neutral)

8. The charges in the wall separate

10. Induction The separation of charge without touching When a charged object is brought near a neutral object, the charges on the neutral object separate.

11. Pith Ball Demo Why are the pith balls attracted to the rod? Fun Fly Stick Demo

12. Electroscope Device to detect charges

13. Induction (negative rod – neutral electroscope) Demo Negative charges move towards bottom and leaves diverge

14. Induction (positive rod – neutral electroscope) Negative charges move towards top and leaves are now positive and diverge

15. Conductors Materials that allow charges to easily flow Ex: Metals Humans Air Water

16. Insulators Materials that do not easily allow charges to flow. Ex: Rubber Glass Wood Plastic

17. Conduction Transfer of charge by contact Only electrons are transferred (lost or gained)

19. Lightning Becomes very “negative” Becomes very “positive”

21. Pith Ball Demo Why do the pith balls repel? Charge is transferred (both are now negative)

22. Electroscope Demo Charge is transferred Electroscope is now negative The leaves repel

23. Grounding The process of connecting a body to Earth to eliminate excess charge.

24. No ground wireGround Wire

28. On dry days we tend to have more trouble with static electricity build-up than on humid (moist) days. Moist days there are more water molecules in the air to steal charge more rapidly. Dry days there are fewer particles in the air to steal charges so we accumulate charge until we touch something and get discharged (shocked).