Byron Dykes, age 10, of Collinsville, OK, for his question:

How does AC travel through electric wires?

Electric current is caused by the activity of electrons in the copper wire. Each of these atomic particles bears a charge of negative electricity. They are so small that it takes two million, million' million, million, million of them to weigh a pound. That figure is two followed by 30 zeros. Naturally, nobody has ever seen a tiny electron, but we can see the result of their busy activity.

Our electric current comes through copper wire, though a few other metals could be used. Copper happens to be just right, mainly because of the setup inside the copper atom. A normal copper atom has 29 electrons. They orbit the nucleus, or core, of the atom in shells o There are two electrons in the inside shell and eight in the second shell. There are 18 electrons in the third shell   which leaves one lone ranger in the outer shell,

This outside lone ranger electron is none too secure. It tends to leave its lonely orbit and perhaps join another copper atom. Every inch of copper wire is made from countless trillions of copper atoms, each with its own restless lone ranger electron. The electric wire is a circuit with its two ends joined to a generator. The generator provides the voltage, the jolt which jogs the lone ranger electrons all through the circuit.

It is these moving electrons which provide the electric current.  To keep a reading lamp going, about three billion, billion of these electrons jog through the wire every second. In DC, which is short for direct current, the electrons are jogging in the same direction.  In AC, which is short for alternating currents they jog in first one direction and then another.

In alternating current, the electrons move together like well trained soldiers   one step forward, one step back. Each back and forth movement is called a cycle. In a 60 cycle current, the little soldiers step forward and backward sixty times in a second. Our everyday electricity comes from this 60 cycle alternating current.

The current in the wire is the energy from countless trillion os jogging electrons. The wire is a circuit running to and from the powerful generator. Anywhere along the line we can tap the circuit and make use of its energy, We open and close the circuit with an electric switch, When the switch is open, the electrical energy may be used to run a toaster, a washing machine, light a lamp or do any one of countless other useful tasks.