Summarizing Conductors and Insulators

Summary

• Polarization is the separation of positive and negative charges in a neutral object.
• A conductor is a substance that allows charge to flow freely through its atomic structure.
• An insulator holds charge within its atomic structure.
• Objects with like charges repel each other, while those with unlike charges attract each other.
• A conducting object is said to be grounded if it is connected to the Earth through a conductor. Grounding allows transfer of charge to and from the earth’s large reservoir.
• Objects can be charged by contact with another charged object and obtain the same sign charge.
• If an object is temporarily grounded, it can be charged by induction, and obtains the opposite sign charge.
• Polarized objects have their positive and negative charges concentrated in different areas, giving them a non-symmetrical charge.
• Polar molecules have an inherent separation of charge.

Glossary

free electron

an electron that is free to move away from its atomic orbit

conductor

a material that allows electrons to move separately from their atomic orbits

insulator

a material that holds electrons securely within their atomic orbits

grounded

when a conductor is connected to the Earth, allowing charge to freely flow to and from Earth’s unlimited reservoir

induction

the process by which an electrically charged object brought near a neutral object creates a charge in that object

polarization

slight shifting of positive and negative charges to opposite sides of an atom or molecule

electrostatic repulsion

the phenomenon of two objects with like charges repelling each other