2. WHY DO SPARKS FLY?
Have you ever been
"shocked" when you touched
a doorknob, a car-door
handle, or a water fountain?
Ouch! Well, then you already
know something about the
effects of static electricity.
The spark is so small that
you probably don’t see it.
There is a huge spark that
you can sometimes see on a
rainy day.
Lightning
3. AN ATOM
To understand what electricity is, you first need to
learn about something that is too small to see: an
atom.
Each tiny atom is made up of even tinier things:
Protons: which have a positive charge
Electrons: which have a negative charge
Neutrons: which have no charge
Electrons move very quickly
around the center of the atom.
4. HOW CAN YOU MAKE ELECTRONS MOVE FROM
ONE ATOM TO ANOTHER?
1. Blow up 2 balloons with air.
2. Tie a short piece of string to each balloon.
3. Rub both balloons with wool sock.
4. Hold the 2 balloons by the string and bring them
together.
What happens?
5. MAKING ELECTRONS MOVE: SPINNING MATCH
EXPERIMENT
How Does the Match Move Without Us
Touching It?
When an object has a negative charge, it will
repel the electrons of other objects and
attract that object’s protons. When the
neutrally charged object is light enough, like
the match in this case, the negatively
charged object will attract the lightweight
object.
Video: http://youtu.be/BFp3NalfKgw
7. MAKING ELECTRONS MOVE
1. Turn on a faucet. The
water must flow in a
steady, narrow stream.
2. What happens when
you hold the same
balloon near the water?
8. BEWARE OF CONDUCTORS!
If you scuff your feet on your living room rug, you pick up extra
electrons and have a negative charge. Electrons move more
easily through certain materials like metal, which scientists
call conductors. When you touch a doorknob (or something
else made of metal), which has a positive charge with few
electrons, the extra electrons want to jump from you to the
knob.
That tiny shock you feel is a result of the quick movement of
these electrons. You can think of a shock as a river of millions
of electrons flying through the air. Pretty cool, huh? Static
electricity happens more often during the colder seasons
because the air is drier, and it's easier to build up electrons on
the skin's surface. In warmer weather, the moisture in the air
helps electrons move off of you more quickly so you don't get
such a big static charge.
So, the next time you get a little shock from touching a
doorknob, you'll know that it's just electrons jumping around.
Think of it as putting a little spark in your life!
9. REFERENCES
Experiments with electricity / by Salvatore Tocci.
http://science-mattersblog.blogspot.com/2010_10_01_archive.html
http://kidshealth.org/kid/talk/qa/electric_shock.html
Editor's Notes
Well, there are two types of electricity. There’s current electricity, which is what makes the lights in your house turn on when you flip a switch. There is also static electricity, which you’ve probably felt on a winter day when you get shocked after touching a metal object, like a doorknob.
In order to understand static electricity, first let’s look at a picture of an atom. All objects are made out of atoms, but they are too tiny for us to see.
Everything on Earth, including you, is made of atoms. Each atom is made of smaller bits called particles. These particles are electrons, protons, and neutrons.
The protons in the center of an atom have a positive charge, and the electrons have a negative charge. An atom usually has the same number of protons (+ charges) and electrons (- charges). Because of this equal number, the atom itself has no charge. However, atoms can develop charges. So how does that happen? Electrons can move from one atom to another. When electrons move, the atom develops a charge. If an atom gains an electron, it develops a negative charge. If an atom gives up an electron, it develops a positive charge.
Static electricity is created when positive and negative charges aren't balanced. Protons and neutrons don't move around much, but electrons love to jump all over the place!
When an object (or person) has extra electrons, it has a negative charge. Things with opposite charges are always attracted to each other, so positive charges seek negative ones and negative ones seek positives. Whew! Got it?
Electrons move because they are attracted to an opposite charged object. http://science-mattersblog.blogspot.com/2010_10_01_archive.html
When an object has a negative charge, it will repel the electrons of other objects and attract that object’s protons. When the neutrally charged object is light enough, like the match in this case, the negatively charged object will attract the lightweight object.