ElectrostaticsElectrostatics

Chapter 21-1Chapter 21-1

Electric ChargeElectric Charge

Explain the atom and the Explain the atom and the charges on an atomcharges on an atom

NeutronsNeutronsProtonsProtonselectronselectrons

Transferring Transferring ChargeCharge

Why is an atom electrically Why is an atom electrically neutral?neutral?

How can it become charged How can it become charged negatively?negatively?

How can it become charged How can it become charged positively?positively?

What does static mean?What does static mean?What is static electricity?What is static electricity?

Conservation of Conservation of ChargeCharge

Charge can be Charge can be transferred from one transferred from one object to another, but it object to another, but it cannot be destroyedcannot be destroyed

Law of Law of ElectrostaticsElectrostatics

What charges attract?What charges attract?What charges repel?What charges repel?Opposite charges attract Opposite charges attract

and like charges repeland like charges repel

Electric FieldElectric Field

The area around a charged The area around a charged objectobject

The area has the same The area has the same charge at the charged objectcharge at the charged object

Strongest nearest the Strongest nearest the electronselectrons

Comparing Electric & Comparing Electric & Gravitational ForcesGravitational ForcesWhich is larger?Which is larger?A thousand trillion A thousand trillion trillion trillion times trillion trillion times larger (10larger (103636))

ConductorsConductors

A material that allows A material that allows electrons to move easily electrons to move easily through itthrough it

won’t retain a chargewon’t retain a chargeSilver is the best, copper, Silver is the best, copper,

metalsmetals

InsulatorsInsulators

A material that won’t A material that won’t allow electrons to pass allow electrons to pass through easilythrough easily

Wood, plastics, glass, Wood, plastics, glass, water, airwater, air

Charging by Charging by ConductionConductionCharging by contactCharging by contactTouch the uncharged object Touch the uncharged object

with the charged objectwith the charged objectResulting charge is the same Resulting charge is the same

as the charging objectas the charging objectTransfer of electronsTransfer of electrons

Charging by Charging by InductionInductionCharging at a distanceCharging at a distanceThe charging object and the The charging object and the

uncharged object don’t uncharged object don’t touchtouch

The resulting charge is the The resulting charge is the oppositeopposite

A temporary chargeA temporary charge

Paper SnipsPaper Snips

LightningLightning

Explain how lightning Explain how lightning formsforms

Where is it safe to be in a Where is it safe to be in a lightning storm?lightning storm?

Safe position if caught far Safe position if caught far from shelterfrom shelter

ThunderThunderLightning produces both light Lightning produces both light

and sound wavesand sound wavesLightning produces great Lightning produces great

amounts of heatamounts of heatAir temperature rises to Air temperature rises to

30,00030,000ooCCCausing air to expand rapidly Causing air to expand rapidly

producing the sound waves.producing the sound waves.

GroundingGrounding

The process of neutralizing The process of neutralizing a charged objecta charged object

Earth is a good ground Earth is a good ground because it is a good source because it is a good source or sink of electronsor sink of electrons

The ElectroscopeThe Electroscope

A device that detects a A device that detects a chargecharge