Electricity 101 Charges Static electricity 1 Electricity describes
Electricity 101 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 • Motion of electrons - The charges are at rest • 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 Tendency of gaining electrons (Negative) Plastic Gold Copper Wood Cotton Wool Glass
Triboelectric series Tendency of gaining electrons (Negative) Plastic Gold Copper Wood Cotton Wool Glass The one higher up on the list gains electrons, therefore is negative
Triboelectric series Tendency of gaining electrons (Negative) 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
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 Start Friction 2 neutral objects 1 charged object Conduction 1 neutral object Action Rubbing Objects have Based on opposite Triboelectric charges series Touching Both objects have the same charge 1 charged object Induction 1 neutral object End Charged objects 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)
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 flow of electrical charges Insulators: substance hat impedes the free flow of electrical charges
Conductors • Metals • Electrolytic solutions – Acids – Bases – Salts
Insulators • • • Wood Air Rubber Plastic Glass Silk
- Slides: 19