Chapter 9 Electrostatics Sections 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.10

9.2 Electrical Nature of Matter Static electricity is a natural phenomena The study of static electricity is elctrostatics.

Continue 9.2 When two objects are rubbed together, they can become charged with electricity. This charge can remain “static,” which means the charge stays where the rubbing took place. This is static electricity.

9.2… Law of electric charges: TEST for electric charges like charges repel one another, unlike charges attract one another, Charged Objects attract neutral object. TEST for electric charges Observe what the object does near an object with a known charge.

How to test for charges We use electroscopes to test for charges. Observe what the object does near an object with a known charge. Ex. If you hold a balloon near a pith ball that you know is negatively charged and it repels from it …you would know that the balloon is neg. Charged objects will attract both opposite charges and neutral!! Charged objects will repel like charges!!

9.2 Electrical Nature of Matter Ensure you know table 1 p. 273, “A model for the electrical nature of matter” Complete questions 1, 2, & 3. p. 273

9.3 Charging by Friction Charging by friction: transferring an electric charge from one substance to another by a rubbing action. One objects shares electrons with another. One is +/ one is -. Think of rubbing a balloon on your head.

Electrostatic Series Be able to read the electrostatic series and know its purpose! The objects at the top will “give up” some of their electrons to the ones underneath them. The greater the distance, the greater the charge is. Example: locate hair and plastic on the series. When you comb your hair(friction) the hair will give up some of its electrons to the comb. Result: hair + comb -

Continue 9.3 friction HowStuffWorks Videos "Transferring Charge: Friction“ Complete questions 1, 2, 3 & 4 p.275

9.5 Transferring Charge by Contact Charging by contact occurs when electric charge is transferred from one substance to another because they touch. One object shares its charge with another – both will have the same charge. refueling incident

9.6 Insulators and Conductors An electrical insulator is a substance in which electrons cannot move freely from atom to atom. An electrical conductor is a substance in which electrons can move freely from one atom to another. Insulators & Conductors explained Answer 1,2,3, & 4 p.281

9.7 Discharging Electrically Charged Objects Answer 1,2, & 3 p. 283

9.7 Discharging Electrically Charged Objects If an object has all excess charges removed, it is said to be discharged. When a charged object is grounded to Earth, it shares its charge with the entire Earth. Discharge at a point is a method of discharging airplanes. Objects can discharge over time by simple exposure to air.

9.8 Induction Transferring electric charge from one substance to another without direct contact is charging by induction. The shifting of electrons within a particle due to a force from another object is induced charged separation. Charging by Induction Video Answer 1,2,3, & 4 p. 287

Induction checklist... know: object with a charge gets close to a neutral object - doesn’t touch charges it with OPPOSITE charge of charged object usually temporarily charged - when charged object leaves, electrons redistribute cam be permanently charged if connected to a grounding wire be able to illustrate

9.10 Lightning Car struck by lightning – BBC Answer 1-6 p.291 Be able to draw a lighting diagram (as in class)