Final answer:
A wooden spoon and a plastic spatula are thermal insulators, while an iron frying pan and a steel fork are thermal conductors. Metals like silver and copper are efficient conductors because of free electrons, whereas wood and plastic are good insulators due to the absence of these electrons.
Step-by-step explanation:
The materials provided can be classified as either thermal conductors or thermal insulators based on their ability to conduct heat. A wooden spoon and a plastic spatula are good examples of thermal insulators because they do not conduct heat well, making them useful for handling hot foods without transferring heat to the user's hand. On the other hand, an iron frying pan and a steel fork are good thermal conductors; they quickly transfer heat, which is why the frying pan is used for cooking and the steel fork can become hot when used with hot food.
Two materials that are good thermal conductors are silver and copper, as they contain many free electrons that can transport thermal energy efficiently. Conversely, two materials that are excellent insulators are wood and plastic. These materials are poor conductors of heat because they lack the free electrons that enable efficient thermal energy transfer, making them suitable for insulating and preventing heat transfer.