Bend
water with your hair
Wash a comb to remove it of any oils. Also wash your hair and
don't use conditioner. Let it dry. Create static electricity on
the plastic comb by combing your dry hair. Turn
on the
faucet so that the water runs slowly but smoothly without breaking
up. Bring the comb near to the running stream of water without
touching it. The charged plastic comb will bend the water stream!
It works because things with the same charge (either positives
or negative) will repel, or push away from each other while two
items with opposite, or different charges (one positive and one
negative)
will attract, or pull towards each other.
Static
electricity is created in the plastic comb when electrons (with
negative charge) move from the atoms of the hair to the comb.
Protons and neutrons in the nucleus of an atom are held together
very
tightly,
but
some of the outer electrons in an atom are held very loosely
and can
move from one atom to another. Some types of atoms hold their
electrons very tightly. Materials made from these atoms are
insulators like cloth, plastic, glass, and hair. Atoms
in other materials have a weak bond with their electrons. Materials
made from these atoms are conductors, like metal.
One
way to move electrons from one object to another is to rub them
together. If they are made of different materials, and are both
insulators,
electrons
will
be
transferred
(or moved) from one to the other. The more rubbing, the more
electrons move, and the larger the charges built up. It is not
the rubbing or friction that causes electrons to move. It is simply
the contact between two different materials.
Rubbing just increases the contact area between them.
So hair and plastic both being insulators means that when a comb
is passed through the hair electrons are transferred from the
hair to the comb. The plastic comb builds up more electrons
than it would normally have - it becomes negatively charged. You
can bend water streams or pick up dust or bits of tissue paper
with
the
charged comb.
Holding the charged comb near a neutral object will make the
charges in that object move. If it is a conductor, many electrons
move
easily
to the other side, as far away as possible. If it
is an insulator, the electrons in the atoms and molecules can
only move very slightly to one side, away from the comb. In
either case, there are more positive charges closer to the negative
comb. Positive and negative charges attract!
Light
a fluorescent light bulb with your hair
WARBNING!: DO NOT
USE ELECTRICITY FROM A WALL OUTLET FOR THIS EXPERIMENT AND BE CAREFUL
NOT TO BREAK THE FLUROESCENT TUBE!
You can light a fluorescent light bulb (but not an incandescent
light bulb - so make sure to use a fluorescent one!) with static
electricity derived from your hair. It works on the
same
principle
as bending
the water stream with a
plastic
comb charged by your hair as above.
Take a light bulb and clean comb into a dark room
(take your clean hair with you too!). Comb your clean, dry hair
to build up a negative charge in the comb. You may need to comb
quite vigorously as you will need quite a lot of charge in the
comb to make this trick work.
Touch the charged part of the comb to the fluorescent
light bulb and watch very carefully. You should be able to see
small
sparks inside the tube/bulb. When the charged comb touches the bulb,
electrons will move from it to the bulb, causing the small sparks
of
light inside. In normal operation, the electrons to light the
bulb
come from
the electrical power lines through a wire in the end of the
fluorescent tube. You may also be able to get light inside the
tube by brining it close to your hair soon after combing. Your
hair has lost electrons to the comb, so it is positively charged.
It can collect electrons from the fluorescent bulb.
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