How Does Static Electricity Work?
Have you ever walked across the room to pet your dog but
got a shock instead? Perhaps you took your hat off on a dry
winter's day and had a "hair-raising" experience! Or maybe you
have made a balloon stick on the wall after rubbing it against
your clothes?
Before understanding static electricity, we first need to
understand the basics of atoms and magnetism.
All physical objects are made up of atoms. Inside an atom are
protons, electrons, and neutrons. The protons are positively
charged, the electrons are negatively charged, and the neutrons
are neutral.
Therefore, all things are made up of charges. Opposite
charges attract each other (negative to positive). Like charges
repel each other (positive to positive or negative to negative).
Most of the time, positive and negative charges are balanced in
an object, which makes that object neutral.
Static electricity is the result of an imbalance between
negative and positive charges in an object. These charges can
build up on the surface of an object until they find a way to be
released or discharged. One way to discharge them is through a
circuit.
The rubbing of certain materials against one another can
transfer negative charges, or electrons. For example, if you rub
your shoe on the carpet, your body collects extra electrons. The
electrons cling to your body until they can be released. As you
reach and touch your furry friend, you get a shock. Don't worry;
it is only the surplus electrons being released from you to your
unsuspecting pet.
And what about that "hair-raising" experience? As you remove
your hat, electrons are transferred from hat to hair, creating that
interesting hairdo! Remember, objects with the same charge
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repel each other. Because they have the same charge, your hair
will stand on end. Your hairs are simply trying to get as far away
from each other as possible!
When you rub a balloon against your clothes, and it sticks to
the wall, you are adding a surplus of electrons (negative charges)
to the surface of the balloon. The wall is now more positively
charged than the balloon. As the two come in contact, the balloon
will stick because of the rule that opposites attract (positive to
negative).
Static Electricity
Try This Experiment . . .
Rub a balloon filled with air on a wool sweater or on your hair.
Then hold it up to a wall. The balloon will stay there by itself.
Tie strings to the ends of two balloons. Now rub the two
balloons together, hold them by strings at the end and put them
next to each other. They'll move apart.
Rubbing the balloons gives them static electricity. When you
rub the balloon it picks up extra electrons from the sweater or
your hair and becomes slightly negatively charged.
The negative charges in the single balloon are attracted to the
positive charges in the wall.
The two balloons hanging by strings both have negative
charges. Negative charges always repel negative charges and
positive always repels positive charges. So, the two balloons'
negative charges "push" each other apart.
Static electricity can also give you a shock. If you walk across
a carpet, shuffling your feet and touching something made of
metal, a spark can jump between you and the metal object.
Shuffling your feet picks up additional electrons spread over your
body. When you touch a metal doorknob or something with a
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positive charge, the electricity jumps across the small gap from
your fingers just before you touch the metal knob. If you walk
across a carpet and touch a computer case, you can damage the
computer.
One other type of static electricity is very spectacular. It's the
lightning in a thunder and lightning storm. Clouds become
negatively charged as ice crystals inside the clouds rub up against
each other. Meanwhile, on the ground, the positive charge
increases. The clouds get so highly charged that the electrons
jump from the ground to the cloud, or from one cloud to another
cloud. This causes a huge spark of static electricity in the sky that
we call lightning.
END OF TEXT
"How Does Static Electricity Work?" In the public domain.
"Static Electricity." In the public domain.
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