Here's why:

* Heat conduction is the transfer of thermal energy through a material due to a temperature difference. The rate at which this energy is transferred depends on the material's properties.

* Thermal conductivity is a measure of how well a material conducts heat. Materials with high thermal conductivity transfer heat quickly, while materials with low thermal conductivity transfer heat slowly.

Here are some examples:

* Metals are generally excellent conductors of heat (high thermal conductivity) because their free electrons can easily carry energy.

* Non-metals like wood, plastic, and rubber are poor conductors of heat (low thermal conductivity) because their electrons are more tightly bound to the atoms.

* Gases are also generally poor conductors of heat because their molecules are far apart and don't collide as frequently.

Factors affecting thermal conductivity:

* Material composition: The type of atoms and their arrangement influence how easily heat can pass through.

* Temperature: Thermal conductivity can change with temperature.

* Density: Denser materials often conduct heat better.

* Presence of impurities: Impurities can disrupt the flow of heat.

In summary: The rate at which materials conduct heat varies significantly, and this variation is determined by their physical properties and the conditions under which they are being used.