What is Electrical Charge?
Electrical charge is not
something you can see,
smell, or weigh. We
know about charge
because we can see its
effects on matter.
All matter is made up of tiny
particles, called atoms. Inside
atoms are even tinier particles.
Some have a negative electrical
charge. Others have a positive
electrical charge. A negative
electrical charge is shown as a
minus sign (-). A positive
electrical charge is shown as a
plus sign (+).
Electric Charge
Some particles
have a negative
electrical charge.
Others have a
positive electrical
charge. Opposite
charges attract
each other. Like
charges repel each
other.
Atoms usually have no overall
charge. This is because the number
of positive charges equals the
number of negative charges.
However, atoms can become
charged. They can pick up electrical
charges from other atoms. This can
happen when you rub two different
materials together – such as balloons
and wool.
Rubbing two different
materials together knocks
negative charges off one
material. This makes the
material positive. The
negative charges collect on
the other material, making it
negative.
The two materials are now
attracted to each other because
they have opposite charges.
Opposite charges attract.
Positives attract negatives.
Negatives attract positives.
Charges that are the same repel,
or push each other away. Two
positive charges repel each other.
Two negative charges do, too.
The buildup of electrical
charge on a material is called
static electricity. The electrical
charges build up because
negative charges have moved
from one material to another.
A balloon has no
overall charge.
There are as many
negative charges
as there are
positive charges.
Rubbing the
balloon knocks
negative charges
off the cloth and
onto the balloon,
making it negative.
The balloon’s negative
charges repel negative
charges in the wall.
This leaves a row of
positive charges on the
outside edge of the
wall. The negatively
charged balloon is
attracted to the wall’s
positive charges and
sticks to it.
After a while
the negative
charges on the
balloon “leak”
away. The
balloon is no
longer
attracted to the
wall. It falls
away.
What are two types of
electrical charges in atoms?
• Answer the question…
– With a partner
– In your Learning Notebook
static electricity
• The buildup of
an electric
charge on a
material.
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