【正文】 . When large numbers of electrons break away from their atoms and move through a wire,we describe this action by saying that electricity is flowing through the ,the electrical fluid that early scientists talked about is nothing more than electrical flowing along a wire. But how can individual electrons be made to break away from atoms? And how can these free electrons be made to along a wire? The answer to the first question lies in the structure of the atoms themselves. Some atoms are so constructed that they lose electrons easily. An atom of copper, for example ,is continually losing an electron, regaining it(or another electron),and losing it again. A copper atom normally has 29 electrons, arranged in four different orbits about its nucleus. The inside orbit has 2 electrons. The next larger orbit has third orbit is packed with 18 electrons . And the outside orbit has only one is this outside electron that the copper atom is continually losing, for it is not very closely tied to the atom. It wanders off, is replaced by another freeroving electron, and then this second electron also wanders away. Consequently,in a copper wire free electrons are floating around in all directions among the copper , even through the copper wire looks quite motionless to your ordinary eye, there is a great deal of activity going on inside it. If the wire were carrying electricity to an electric light or to some other electrical device, the electrons 7 would not be moving around at random. Instead, many of them would be rushing in the same directionfrom one end of the wire to the other. This brings us to the second question .How can free electrons be made to move along a wire? Well ,men have found several ways to do that .One way is chemical. Volta,s voltaic pile,or battery, is a chemical device that makes electricity(or electrons)flow in wires. Another way is magic. Faraday and Henry discovered how mags could be used to make electricity flow in a wire. Mags Almost everyone has seen horseshoe magsso called because they are shaped like horseshoes. Probably you have experimented with a mag, and noticed how it will pick up tacks and nails, or other small iron objects. Men have known about mags for thousands of years. Several thousand years ago, according to legend, a shepherd named Magnes lived on the island of Crete, in the Mediterranean Sea .He had a shepherds crook tipped with iron. One day he found an oddly shaped black stone that stuck to this iron , when many other such stones were found, they were called mags(after Mags).These were natural mags. In recent times men have learned how to make mags out of iron. More important still, they have discovered how to use mags to push electrons through wiresthat is, how to make electricity flow. Before we discus