Just For Starters

摘要

Materials that can conduct current (silver, gold, aluminum, copper, etc.) contain large numbers of loosely held electrons. Their resistance to the flow of current is measured in just a few millionths of an ohm per centimeter. Insulators — such as glass, rubber, and plastic — have very few loosely held electrons and their resistance to the flow of current is measured in a few million ohms per centimeter.