What is Static What is Static Electricity?Electricity?

Static Electricity is…Static Electricity is… A stationary build-up of electric A stationary build-up of electric

charge (electrons) on a material charge (electrons) on a material Electricity that does not move (static Electricity that does not move (static

vs. dynamic)vs. dynamic) Shocking!Shocking!

Types of ChargesTypes of Charges Most objects are neutral – electrically Most objects are neutral – electrically

unchargeduncharged If 2 neutral objects are rubbed If 2 neutral objects are rubbed

together, one becomes positively together, one becomes positively charged (loses electrons) and the charged (loses electrons) and the other becomes negatively charged other becomes negatively charged (gains electrons)(gains electrons)

Direction of electron flow called the Direction of electron flow called the “ELECTROSTATIC SERIES”“ELECTROSTATIC SERIES”

The Electrostatic SeriesThe Electrostatic Series AcetateAcetate GlassGlass WoolWool Fur/HairFur/Hair Ca, Mg, PbCa, Mg, Pb SilkSilk AluminumAluminum ZincZinc CottonCotton Paraffin waxParaffin wax EboniteEbonite PlasticPlastic C, Ni, CuC, Ni, Cu SulfurSulfur Gold, Gold,

PlatinumPlatinum

Weak hold on electrons

Strong hold on electrons

The Electrostatic SeriesThe Electrostatic Series AcetateAcetate GlassGlass WoolWool Fur/HairFur/Hair Ca, Mg, PbCa, Mg, Pb SilkSilk AluminumAluminum ZincZinc CottonCotton Paraffin waxParaffin wax EboniteEbonite PlasticPlastic C, Ni, CuC, Ni, Cu SulfurSulfur Gold, Gold,

PlatinumPlatinum

For example:A plastic comb is rubbed with wool

•The wool gives up electrons (weaker hold); becomes positively charged•The plastic comb takes electrons and becomes negatively charged

Let’s try another one…Let’s try another one… AcetateAcetate GlassGlass WoolWool Fur/HairFur/Hair Ca, Mg, PbCa, Mg, Pb SilkSilk AluminumAluminum ZincZinc CottonCotton Paraffin waxParaffin wax EboniteEbonite PlasticPlastic C, Ni, CuC, Ni, Cu SulfurSulfur Gold, Gold,

PlatinumPlatinum

Your cotton sweater rubs against your silk shirt…

Negative charge:• Cotton (gained electrons)

Positive charge:• Silk (lost electrons)

How to put static charge on How to put static charge on an objectan object

1.1. By ContactBy Contact Touch something with a charged objectTouch something with a charged object

Positively charged object will take some Positively charged object will take some electrons from neutral object, making it electrons from neutral object, making it positive toopositive too

Negatively charged object will give Negatively charged object will give electrons to the neutral object, making it electrons to the neutral object, making it negative too negative too

Charging by ContactCharging by Contact1.1. FrictionFriction

Between any two Between any two materialsmaterials

Rubbing it with Rubbing it with somethingsomething

Charging by ContactCharging by Contact2.2. ConductionConduction

When 2 objects When 2 objects with different with different amounts of amounts of charge come into charge come into contactcontact

Electrons move Electrons move from one object from one object to the otherto the other

How to put static charge on How to put static charge on an objectan object

3.3. By InductionBy Induction Bring a charged object near a Bring a charged object near a

neutral object neutral object without touching itwithout touching it

Let’s check out the electroscope!Let’s check out the electroscope!

Charging by InductionCharging by Induction Bringing a charged rod near the Bringing a charged rod near the

electroscope will INDUCE the same electroscope will INDUCE the same charge on the silver leafcharge on the silver leaf

Negative rod forces electrons down Negative rod forces electrons down and makes the leaf negativeand makes the leaf negative

Positive rod attracts electrons up Positive rod attracts electrons up and makes the leaf positiveand makes the leaf positive