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How does electricity work?
Answer 1:

Nice question about electricity. It is always good to question things that we use in everyday life.

This is a subtle and difficult question to answer. Let us see if we can ask some different questions and to understand it!

-What makes my walkman work? A battery! And somehow we are told that this contains electricity.

-What makes my lights shine? By plugging it into an outlet! Again we are told that this is electricity, but somehow this form of electricity seems different from the kind in my walkman. So, we are stuck. Does my battery or does my outlet contain electricity? If we assume one and not the other,then we are confronted with fact that some appliances can use batteries or an outlet.

So, let us say that both batteries and outlets contain electricity, but indifferent forms. Since we are concerned with what electricity is and not what its various forms are, let us ask how these two forms are the same.

-What happens when I stick my finger in an outlet? (Mark's note: DO NOT DO THIS! YOU WILL ELECTROCUTE YOURSELF.) Besides feeling really stupid, I feel a strange jolt, almost like something is moving through me. If I hold the battery in a similar way I don't feel anything. But, if I go to my car battery and do the same thing I feel a similar jolt as the outlet. So,perhaps a similarity between the two types of electricity is that both involve the flow of something. But, what is this thing and how does it flow?

(Here is where the whole thing gets technical and you will have to take my word on it. But, centuries ago people asked themselves these same questions and centuries later, we have a set way of speaking about all of these things. So, bear with me while we go through some vocabulary.)

Scientist have found that this flow is the flow of something called electrons and electrons have a property know as charge. It is this charge that transmits the energy to your walkman and your lights that they need to do what we expect them to. Another remarkable feature of charge is that it comes in two forms: "positive" and "negative" or "plus" and "minus".
These two forms of charge are very particular about who they hang outwith. Plusses hate plusses and minuses hate minuses so they stay away from one another or repel. But, plusses and minuses get along great and attract. Now these electrons have a negative charge and so if we want them to move we have to build up a negative charge close to them so that they run away. This is not an easy task and so I won't try to explain to you how it is that people get batteries and outlets to work. Instead we will delve into more interesting questions.

-Why do electrons have charge and nothing else does? Electrons aren't the only thing that have charge. In fact many other things do, but electrons are the most abundant and easy to work with "charge carriers" that we have around, and so almost all electrical devices use them. That is why we call them electrical! In fact electrons are so abundant that they are in EVERYTHING that you touch and see. The reason that everything doesn't have a HUGE charge is that all of these electrons come in pairs with protons which have an equal positive charge and the two cancel each other.

-How is it that electrons get charge? They are born with it, so to speak.
Charge is something that cannot be created or destroyed, so there has been the same amount around today as when the universe began (we think!). It is a good thing that there is a lot of it, or we wouldn't get to listen to music very often and it would all be classical! Every worse, we wouldn't be around at all!!

-But where did this charge come from, how did it get here? I wish that I knew. But, science hasn't come to understand this question yet!

I hope that this answers some of your questions about electricity. If nothing else I hope you learn to keep your fingers out of electrical outlets!

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University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships