During the inspection of industrial control cabling, an electrical technician notes that the cable consists of an annealed copper core surrounded by a polyvinyl chloride (PVC) jacket. What fundamental atomic property explains why the copper core acts as a conductor while the PVC jacket acts as an insulator?
- ACopper atoms have four valence electrons that form a rigid covalent matrix, while PVC molecules have a single loosely held electron per atom.
- Copper atoms possess loosely bound valence electrons that drift freely under an electric field, while PVC molecules hold their valence electrons tightly in stable chemical bonds.Answer
- CCopper atoms conduct electricity through the migration of positive atomic nuclei, while PVC blocks only negatively charged particles.
- DCopper atoms maintain completely filled outer valence shells of eight electrons, while PVC molecules contain unfilled shells with high free electron mobility.
Answer
Copper contains loosely bound valence electrons that drift freely when voltage is applied, whereas PVC holds its valence electrons tightly within stable chemical bonds, preventing electron flow.
Good electrical conductors such as copper have outermost valence electrons that are loosely held by the nucleus, allowing them to detach easily and drift as an electric current under an applied electromotive force. In contrast, insulating materials such as PVC hold their valence electrons tightly in stable chemical bonds, leaving virtually no free charge carriers available to conduct electricity.
Step-by-Step Solution
Key Concept
Valence electron mobility in conductors versus insulators
Estimated Time:45s