Don Williams age 1l? of Seattle, Washington, for is question:
What is electricity made of?
Suppose we could go back in time and squat with a caveman beside his campfire. To test how smart he was, you might ask him what fire is made of. If he answered at all, he might say it was made of sticks logs and dry leaves Chances are he was too busy learning how to use and control fire to bother much about what it was made of or what made it work.
Mankind had been using fire for thousands of years before he discovered that it is a form of energy released when solid things break apart into small particles of gases and water vapor. As history goes, we have only recently started using the power of electricity. It is not surprising that we have not yet learned all there is to know about it.
About 50 years ago, it was discovered that electricity is caused by the activity of minute electrons. These are the particles that whirl in shells around the nucleus of the atom. A simple copper atom has 29 electrons. Two whirl around the inside shell and eight in the shell outside it. The third shell is complete with 18 electrons. Those three shells have their full quota of electrons, But the copper atom still owns one more electron.
This lone ranger starts a new outer shell all by itself. Such one man shells are never very securely attached to the atom. They tend to move about and, in this case, often exchange places with other lone rangers of nearby copper atoms. These are the electrons which are pressed into service to make electric current flow through the wires,
The push which lines them up and sets them marching is called voltage. It is the power which is generated by great dynamos. The first dynamo was a simple horseshoe magnet and a copper disc turned by a hand crank. As the copper disc turned through the magnetic field it cut the lines of magnetic force and produced voltage. A copper wire ran from the dynamo in a circuit, round and back to it, So long as the circuit was unbroken and the disc turned, it produced voltage which pushed the electric current through the wire, Our biggest generators still work on the same principle. While we cannot say that electricity is made of the magnets and copper coils which generate the voltage. We cannot say it is made of the lone ranger electrons which chase around the circuit of wires for, so far as we knows they are not used up. We do not even know how or why the voltage starts them going. We know how to make and use electricity, but we do not yet know all there is to know about it. Just as the caveman knew how to make and use fires without knowing what it actually was.