Question

The best conductor of heat is?
A. Silver
B. Bronze
C. Aluminum
D. Copper

Answer 1

Hint:Heat conductivity is the rate at which heat can be transferred inside a material. More the rate of transfer of heat more is the material’s heat conductivity. A material which has the most number of free electrons has the highest heat conductivity, which is why metals have more thermal conductivity.

Complete answer:
 Heat conductors are the materials which transport the heat inside the material easily. When a material allows heat to flow from it, then they are good conductors of heat. Normally metals are good conductors of heat. This is because metals contain free electrons. When these metals are exposed to a heat source, then these free electrons gain kinetic energy from the heat, and hence they get excited and start moving from one place inside the material to another.

 The electrons collide with the hot atoms and they get kinetic energy and pass to other atoms and hence in this way, heat is conducted in the material. Thus, less the number of free electrons, less would be the heat conduction in a metal. Non metal and semi metals are heat insulators and have low thermal conductivity respectively because of the lack of free electrons in them.

Among the metals in the question, one which is the best conductor of heat is silver. It has a thermal conduction value of 430W/mK. Other metals which are really good conductors of heat are gold and silver.

Note: In general, we use copper wires in communications such as in telephone cable lines, cooking pots and kettles. Even though gold and silver are better conductors of heat than copper, they are not used in abundance because of their less availability and high price of these metals. However, gold or silver is used in aerospace connections.