Charges Static electricity

1. Electricity describes all phenomena caused by positive and negative charges Static Electricity Dynamic Electricity Transfer of electrons from one object to another The charges are at rest Motion of electrons Charges are in motion

2. Negatively charged bodies contain more electrons (-) than protons (+) Positively charged bodies contain more protons (+) than electrons (-) A neutral object contains the same amount of protons (+) and electrons (-)

3. We can charge objects by… i) Friction ii) Conduction iii) induction

The basics Only electrons move from object to object I’m Outta Here Goodbye !!

i) By Friction One material rips the electrons off another material, after rubbing the two together

To Summarize… 2 Neutral Objects Get rubbed together (Friction 1 rips the electrons from the other 1 positive object and 1 negative object

Triboelectric series Plastic Gold Copper Wood Cotton Wool Glass Tendency of gaining electrons Plastic Gold Copper Wood Cotton Wool Glass (Negative)

Triboelectric series Plastic Gold Copper Wood Cotton Wool Glass Tendency of gaining electrons Plastic Gold Copper Wood Cotton Wool Glass The one higher up on the list gains electrons, therefore is negative (Negative)

Triboelectric series Plastic Gold Copper Wood Cotton Wool Glass Tendency of gaining electrons Plastic Gold Copper Wood Cotton Wool Glass Gold (-) and Wood (-) will repel Gold (-) and Cotton (+) would attract Gold (-) and Wool (+) would attract Wood (-) and Cotton (+) would attract Wood (-) and Wool (+) would attract Cotton (+) and Wool (+) would repel (Negative)

ii) By Conduction One already charged object, « shares » its charge with a neutral object that it has touched

iii) By Induction One already charged object, « splits» the charges of a neutral object without touching

To Summarize Friction Conduction Induction Start Action End Charged objects Friction 2 neutral objects Rubbing Objects have opposite charges Based on Triboelectric series Conduction 1 charged object 1 neutral object Touching Both objects have the same charge Induction Not touching Charged object still charged Neutral object has seperated charges

4. Electrical charges of like signs repel, while electrical charges of opposite signs attract

Neutral objects always attract (induction) - e- n o + + - p+ - n o + + -

To summarize… Objects of similar charge will repel Objects of opposite charges will attract A neutral object will always be attracted to a charged object A B B C

5. Conductors:. substance that allows the free 5. Conductors: substance that allows the free flow of electrical charges Insulators: substance hat impedes the free flow of electrical charges

Conductors Metals Electrolytic solutions Acids Bases Salts e-

Insulators Wood Air Rubber Plastic Glass Silk e-