Unit 3: Characteristics of
Electricity
Chapter 9: Static Electricity
p 294-321
Static Electricity Terms
9.1
•charged
9.2
•law of attraction
•electric charge and repulsion
•static
electricity
•
•positive charge
•electrostatics
•negative charge
•neutral
•insulator
•conductor
9.3
•spark
•ground
•lightning
•lightning rod
•electroscope
•induction
•electrostatic
precipitator
The Law of Conservation of Charge
• The net charge of an isolated
system remains constant.
• Under normal conditions,
charges are not created nor
destroyed.
• Under certain conditions,
pairs of oppositely charged
particles can form and
annihilate each other
Charging = Separation of Charge
• Charging by Rubbing
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Observation
When two different substances are rubbed together, they each attract some
objects, like saw dust.
Before they were rubbed together, they did not attract anything.
Theory
Some electrical charges are transferred from one object to the other.
One substance holds onto electric charge stronger than the other, so one takes
some electric charge from the other.
The other substance does not hold onto their electric charges as tightly, so it loses
some of those charges.
The amount of electrical charges gained by one is the same as the amount lost by
the other. As a result, the pair of objects have equal but opposite charges.
Static Electricity
and Current Electricity
•
Charged
the property of an object that has an imbalance of electrical charge.
 It is either positively charged or negatively charged; it is not neutral.
•
Neutral
net
has equal amounts of positive and negative charges so that it has no
(total) charge.
• Static Electricity = stationary charges
•
unbalanced charges stay on the surface of same object and do not flow
• Current Electricity = moving charges
•
electric charges move through a substance
•
Electrostatics
the scientific study of static electricity
Conductors and Insulators
• Insulators
• materials that do not conduct electric charges;
• any excess charge stays on the surface (static)
• Conductors
• materials that allow electric charges to move freely
• Lightning and sparks are bursts of electric charges that
travel from a conductor through the air to a charged
static insulator.
Bending Water Investigation
• Identify the combination of household items
that affects water the greatest.
• Describe your method of testing.
• Conduct further experiments (play).
• Describe your tests and results
• DUE WEDNESDAY