Iron is a good conductor of heat, meaning it allows heat to pass through it efficiently, unlike wood, plastic, and rubber, which are insulators.

Conductor of Heat
Wood, plastic, iron, and rubber are all materials with different properties when it comes to conducting heat. Among these options, iron is the best conductor of heat. Here's why:

Conduction of Heat
- Heat conduction is the process where heat energy is transferred from one substance to another through direct contact.
- Materials that are good conductors of heat allow heat to pass through them easily.

Iron as a Conductor of Heat
- Iron is a metal that has a high thermal conductivity, meaning it can transfer heat efficiently.
- When heat is applied to iron, its particles vibrate and transfer the heat energy to neighboring particles quickly.
- This property is why iron is commonly used in cooking utensils, radiators, and other applications where heat transfer is necessary.

Comparison with Other Materials
- Wood and plastic are poor conductors of heat, which is why they are often used as insulating materials to prevent heat transfer.
- Rubber is also a poor conductor of heat, making it suitable for applications where heat insulation is required.

Conclusion
In conclusion, iron is the best conductor of heat among the given options. Its high thermal conductivity allows for efficient heat transfer, making it a common choice for various applications where heat conduction is essential.