Electrical Conductors
Even if you're never going to repair a lamp or make a chick brooder, you should know about conductors and insulators. This is because you happen to be a fairly good conductor of electricity. Electricity will pass easily through you to other conductors—the ground, for instance. When this happens you may get a shock, burn, or serious injury. But it doesn't ever have to happen, if you learn to understand your friend, electricity.
Silver, copper, iron, aluminum and many other metals are very good conductors. Water, acids, and salts are too. Electricity passes over or through them very easily. Like water pipes, the larger the conductor, the more electricity it can carry. When conductors are too small for the amount of electrons trying to move over them, they get hot, melt, may start fires. That's why wire size is important.