Which of the following materials is a good conductor of electricity?

Copper is recognized as an excellent conductor of electricity due to its unique properties. It has a high density of free electrons that can move easily in response to an electric field, which allows electrical current to pass through with minimal resistance. This quality makes copper one of the most commonly used materials in electrical wiring and components.

In contrast, rubber, plastic, and wood are considered insulators, meaning they do not conduct electricity effectively. These materials lack the free-moving electrons necessary for conducting electrical current, which is why they are often used to cover or insulate electrical wires and components, preventing accidental electric shocks or short circuits.