A conductor is a material that is able to transmit heat efficiently, while an insulator is a material that is poor at conducting heat.
Good conductors of heat include:
Metals: Most metals are good conductors of heat, including copper, aluminum, silver, iron, and steel. These materials are able to transmit heat quickly and efficiently due to the way their atoms are arranged.
Graphite: Graphite is a form of carbon that is also a good conductor of heat, with a thermal conductivity of around 1000 W/m-K.
Water: Water is a good conductor of heat, with a thermal conductivity of around 0.6 W/m-K.
Bad conductors of heat, or insulators, include:
Air: Air is a poor conductor of heat, with a thermal conductivity of around 0.024 W/m-K. This is due to the widely spaced molecules and constant motion of the molecules in air.
Glass: Glass is a poor conductor of heat, with a thermal conductivity of around 1 W/m-K.
Plastic: Plastic is also a poor conductor of heat, with a thermal conductivity that can range from around 0.2 W/m-K for some types of plastic to around 0.5 W/m-K for others.
Wood: Wood is a poor conductor of heat, with a thermal conductivity of around 0.1 W/m-K.
Rubber: Rubber is a poor conductor of heat, with a thermal conductivity of around 0.05 W/m-K.
In general, materials that are poor conductors of heat are called insulators. Some common insulators include:
- Air
- Glass
- Plastic
- Wood
- Rubber
Among these options, air is typically the poorest conductor of heat. Materials such as glass, plastic, wood, and rubber are also poor conductors of heat, but they are not as effective as insulators as air.
Air is generally considered to be the poorest conductor of heat among common materials. This is because air is made up of molecules that are widely spaced apart, which makes it difficult for heat to be transmitted through the material. In addition, the molecules in air are in constant motion, which also helps to impede the flow of heat.
The thermal conductivity of air is very low, typically around 0.024 W/m-K. This means that it is a poor conductor of heat and an effective insulator.
There are other materials that are even poorer conductors of heat than air, such as vacuum and certain types of foam insulation. However, these materials are not as commonly used as air in practical applications.
Overall, the low thermal conductivity of air makes it an effective insulator, which is why it is often used in applications where heat needs to be retained or kept out, such as in the insulation of buildings or the walls of a thermos.
If you are looking for a metal that is a poor conductor of heat, you might consider a material such as bismuth, which has a relatively low thermal conductivity of around 0.25 W/m-K. This makes it a relatively poor conductor of heat compared to other metals. Other metals that are poor conductors of heat include lead, tin, and zinc.
It's important to note that the conductivity of a material can vary depending on its temperature and other factors. For example, a metal that is a good conductor of heat at room temperature may become a poor conductor at very low or very high temperatures.
