Clothes tumble in the dryer and cling together,
Shocks from a door knobs after walking across carpet,
Sparks of electricity after pulling off clothes,
Bolts of lightning across the sky,
A bad hair day…
 Protons
• found in the nucleus of atoms
• positive charge
 Neutrons
• found in the nucleus of atoms
• no charge
 Electrons
• found outside the nucleus
• negative charge
 There
are particles smaller than this-Quarks
-organization of quarks determines the type of
particle
 Electrons
are removed and added to
atoms to give them charge
 The
number of electrons that surround
the nucleus determines the charge and
amount of charge.
 Positive
- possesses less electrons than protons
 Negative
- possesses more electrons than protons
 Neutral
- equal number of electrons and protons
 Charge
is measureable
 Unit of charge- Coulomb (symbol is C)
• THIS IS A VERLY LARGE AMOUNT OF
CHARGE
 The
charge on single electron
-1.6x10-19 C
• Proton is the same magnitude but positive
•
 If
an object has an excess of 1x105
electrons. What is the charge on that
object? (each electron has -1.6x10-19 C)
 Opposites
Attract
 Likes
Repel
 Any
charged object – positive or
negative, will have an attractive
interaction with a neutral object
 Example:
Paper pieces
FORCE OF REPULSION
1 WAY

objects can repel each
other is if they are both
charged with the same type
of charge
FORCE OF ATTRACTION
2 WAYS


One object is neutral and
the other object is charged
Both objects are charged
with opposite charges
CONDUCTORS
 Materials that allow
electrons to transfer across
the entire surface of an
object
INSULATORS
 Materials that do not allow
electrons to transfer across
the surface of an object
 The charge will remain at
the location of charging
CHARGE TRAVELS ON THE OUTSIDE SURFACE OF A
CONDUCTOR
 The
process of separating opposite
charges within an object
A
charged object can cause electrons to
move within an object so that one side is
positive and the other side is negative
 The
object remains neutral
 Uncharging
 Removing
excess charge on an object by
means of the transfer of electrons
between it and another object of
substantial size (your body, the earth,
etc.)



Rubbing an Object
Two objects have equal
and opposite charges
Transfer occurs from
the least electronloving material to the
most electron-loving
material


Charge the
neutral object
by contact
with a charged
object
Both objects
have the same
type of charge
as the initially
charged
object
 Method
to charge an
object without
actually touching the
object to any other
charged object
 The
object being
charged receives a
charge that is
opposite that of the
charged object
Negative Charge
Positive Charge
 Electrophorus
 Exist
around any object carrying a
charge
 The
direction of the electric field is
always directed the way a positive test
charge would be pushed or pulled if
placed in the space surrounding the
source charge
 Coulomb’s
Law gives a mathematical
description for the force associated with two
point charges
“F” is the magnitude of the force experienced
 “k” is Coulomb’s constant: 9.00x109 Nm2/C2
 “Q” are the two charged objects
 “d” is the distance between the centers of the
objects
 The direction of the force depends on the charges
involved

A
charge of +3.00 C and -2.50 C are
placed 1.50 m apart. How much force of
attraction is between them? (k = 9.00 x
109 Nm2/C2)
Negative Charge
Positive Charge
 Always
extend from a positively charged
object to a negatively charged object (when
there are 2 charges)
 Starts from a positively charged object to
infinity (1 charge)
 Starts from infinity to a negatively charged
object (1 charge)
 Never
 Are
cross one another
most dense around object with the
greatest amount of charge
 Several
electric field line patterns are
shown in the diagrams below. Which of
these patterns are incorrect?
 Consider
the electric field lines shown in
the diagram below. From the diagram, it
is apparent that object A is ____ and
object B is ____.
 Consider
the electric field lines drawn at the
right for a configuration of two charges. Several
locations are labeled on the diagram. Rank
these locations in order of the electric field
strength - from smallest to largest.
