Question

Answer:
The materials which allow heat to pass through them easily are
conductors of heat. For examples,aluminum, iron and copper.

The materials which do not allow heat to pass through them easily are poor conductors of heat such as plastic and wood. Poor conductors are known as insulators

Answer 1

HEY!!

The materials which allow hey to pass through them easily are called conductors.

The materials which do not allow heat to pass through them are called as insulators.

Answer 2

The materials facilitating transfer of heat  are called heat conductors and the materials which do not transfer heat are called insulators.

Explanation:

• Heat Conductors are substances which have free electrons, atoms and minute substances  within them which carry the thermal energy through the material thereby conducting heat.
• The conduction takes place by collusion of free electrons, atoms and molecules present in the material which produces minor kinetic and potential energies. Metals are elements with free substance hence they are very good conductor of heat.
• Heat Insulators are substances which do not have these free substances and hence don't transfer heat to its surrounding objects.
• These are densely packed materials hence are poor conductors or do not conduct at all. Fiberglass is the best insulator, plastics, wood etc are other examples of insulators.