Diane Sanders, age 14, of Channelview, Texas, for her question:
What exactly is electricity?
We know how to generate it and we most certainly know how to make use of it. Scientists can explain what is necessary to make it work. They also explain that electricity is a form of energy. But nobody can say what it actually is. In fact, people learned how to generate and use it long before they knew the first thing about what goes on behind the scenes.
Basically, electricity is a form of energy that a tiny atom uses to hold itself in shape. Down in the mini world of atomic particles, there are two opposite kinds of electrical energy called positive and negative. Each proton particle in the nucleus bears a positive charge. Each electron particle, orbiting the nucleus, bears an equal and opposite negative charge.
The secrets of our electricity are in the little electron. In a cloud chamber, this invisibly small particle leaves a trail which proves that it bears a negative charge. It has been estimated that the number of these midgets in a pound is trio followed by 15 zeros. The energy of one electron is negligible. But the combined energy of 10,000 billion billion electrons can be harnessed to keep a light bulb burning for one hour.
The trick is to pry zillions of electrons from their atoms and organ¬ize them to move in the same direction. Some atoms are more helpful in this matter than others. For example, our electrical wires are made of copper because each copper atom has one rather loosely attached electron. It can be jolted free and made to march in an electric current.
The jolting is called voltage. It pushes zillions of electrons through a wire circuit. In a battery, the voltage jolt is provided by chemicals. In a generator, it is produced when copper coils cut continuously through the field of energy around a magnet. An electric current gets going when the two ends of a wire loop are connected to the battery ox generator. The wire must be an unbroken circuit.
Nobody knows exactly how voltage power pushes zillions of energetic electrons through a wire circuit. But it does and we can make it work to give us different types of electric current. In direct current, the moving electrons march together in the same direction. In alternating current, they march in step, jogging back and forth at so many times per second.
In some miraculous way, the combined energy of teeming electrons charge the wire circuit with electric current. Along the circuit, we set up outlets and plug into this electrical energy.
Giant generators have enough voltage power to push teeming electrons through wire circuits hundreds of miles long. Most of them are adjusted to generate alternating current, in which the electrons jog to and fro. Chances are, the billions of energetic electrons that light a reading lamp jog back and forth sixty times every second.