Electricity 101Charges

Static electricity

1. Electricity describes all phenomena caused by positive and negative charges

Static Electricity- Transfer of electrons

from one object to another

- The charges are at rest

Dynamic Electricity• 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) Conductioniii) induction

The basics

• Only electrons move from object to object

I’m Outta HereGoodbye !!

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

PlasticGoldCopperWoodCottonWoolGlass

Tendency of gaining

electrons

(Negative)

Triboelectric series

PlasticGoldCopperWoodCottonWoolGlass

Tendency of gaining

electrons

(Negative)

The one higher up on the list gains electrons, therefore is negative

Triboelectric series

PlasticGoldCopperWoodCottonWoolGlass

Tendency of gaining

electrons

(Negative) 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 SummarizeStart Action End Charged

objects

Friction2 neutral objects Rubbing

Objects have opposite charges

Based on Triboelectric series

Conduction

1 charged object

1 neutral object

TouchingBoth objects have the same charge

Induction

1 charged object

1 neutral object

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

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Insulators

• Wood• Air• Rubber• Plastic• Glass• Silk

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