Transcript Electric Charge_student

Electric Charge
and
Static Electricity
Page 30
Essential questions

1. What is the connection
between parts of an atom
and charged particles?

2. What characteristics
define electric currents?
ATOMS and charge

Atoms ARE MADE OF PARTICLES:

Protons are LOCATED ________


Neutrons are located _______


Protons have a ______ charge
Neutrons have a _____ charge
Electrons are located _______

Electrons have a _____ charge
Review time
Electrons are found
inside the nucleus.
True or false
Correct answer is
false
Law of electric charge
Electric forces are created between all
electric charges.
 Because there are two kinds of charge
(positive and negative) the electrical force
between charges can attract or repel.

Electric force


Is the force between charged
objects.
Strength is determined by 2
factors:

The size of the charges.

Distance between charges
Electric field



Is a region around a charged
particle that can exert a force
on another charged particle.
Objects become charged because
the atoms in the objects can
gain or lose electrons.
If the atoms lose electrons the
object becomes (+). If the atoms
gain electrons the object
becomes (-).
How objects become charged

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Friction-rubbing of 2 objects
together
Conduction- occurs when
electrons are transferred from 1
object to another by direct
contact.
Induction- occurs when an
uncharged object are
rearranged without direct
contact with a charged object.
Conservation of charge



when you charge objects by any
method, no charges are created
or destroyed. Electrons simply
move from 1 atom to another.
This produces objects or regions
with different charges.
Since charges are not created or
destroyed, charge is said to be
conserved.
Detecting charge

To determine charge use an
electroscope.
Moving charges
2 groups- conductors &
insulators.
 Conductor- is a material in
which charges can move
easily. Mainly metals.
 Examples- copper, silver,
aluminum, and mercury
 Water is a conductor

insulators
Insulator- is a material in
which charges cannot move
easily.
 Electrons are tightly bound
to atoms.
 Examples- plastic, rubber,
glass, wood, and air.

Static electricity
S. e. – is the buildup of
electricity charges on an
object.
 If an object is static it is not
moving.
 Electric discharge – the loss
of static electricity.

lightning

Example of
electric
discharge

Figure 6 page 479
LIGHTNING
Lighting rod- is a pointed
rod connected to the
ground by a wire.
 Lightning rods are
“grounded” meaning they
are in contact with earth.
 Earth absorbs charge so no
damage is done to buildings.

Things to
remember

Charge is a
physical
property.
Objects with a
(+) or (-) charge
exert a force
on other
charged
objects


Lightning and
the shock you
receive from a
doorknob are
example of
electric
discharge.
What is a
conductor/
insulator?
Electrical
energy
Section 2



Electrical energy- the
energy of electric
charges.
Electric current- flow of
electrical charges.
One common way to
produce electric current
is through chemical
reactions in a battery.


Cell- is a device that
produces an electrical
current by converting
chemical energy to
electrical energy.
Battery- converts
chemical energy into
electrical energy and is
made of several cells.
Parts of a cell

Every cell
contains a
mixture of
chemicals that
conducts a
current.


The mixture is
called an
electrolyte.
Chemical
reactions in the
electrolyte
convert
chemical energy
into electrical
energy.
Parts…..

Electrode- is the part of a
cell through which charges
enter or exit.
Cell types
Cell are divided into 2
groups.
 Wet cells- contain liquid
electrolytes. (example car
battery)
 Dry cells- contain
electrolytes that are solids
or paste-like. (ex. Batteries)

Terms
Potential difference- energy
per unit charge; specifically,
the difference in energy per
unit charge as a charge
moves between 2 points in an
electric circuit.
 Measured in volts

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Photocell- is the part of a
solar panel that converts
light into electrical energy.

Thermocouples- used to
monitor the temperature of
car engines, furnaces, and
ovens.