State the Materials : good conductor/ poor conductor:
1. Iron rod/nail
2. sulphur
3. Coal piece
4. Copper wire

Hint :The materials or substances that enable electricity to flow through them are known as conductors. They conduct electricity because electrons can easily flow from atom to atom within them. Conductors often allow heat or light to be transferred from one source to another.

Complete Step By Step Answer:
Good conductor- A conductor is a substance that easily allows electricity to move through it. Silver, in particular, is an excellent electrical conductor. Silver, copper, and other metals are excellent conductors.
Poor conductor- Materials that do not allow electricity to pass through them are known as bad conductors. Rubber, glass, and wood, for example, are poor conductors.
1. Iron rod/ nail - Metallic bonds exist in iron, which allow electrons to freely pass through multiple atoms. This is referred to as delocalization. Iron rod/ nail is a good conductor as a result of this.
2. Sulphur- Sulphur is classified as a non-metal since it possesses three of the non-metal physical properties. Since electrons are not free to pass, it is a weak heat and electricity conductor.
3. Coal piece- Coal is a decent conductor of heat and a bad conductor of electricity.
4.Copper wire: The electrons are free to pass around in the metal. As a result, they are referred to as free electrons. They're also called conduction electrons because they aid copper's ability to conduct heat and electricity well.

Note :
Mercury is a bad heat conductor but a good electrical conductor. Mercury has a special electron structure that makes it behave similarly to noble gas elements when an electron is removed. Mercury forms weak bonds as a result, and is a liquid at room temperature.