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The thermal conductivity of a material is a measure of its ability to conduct heat.It is commonly denoted by , , or and is measured in W·m −1 ·K −1.. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal conductivity.
In heat transfer, the thermal conductivity of a substance, k, is an intensive property that indicates its ability to conduct heat. For most materials, the amount of heat conducted varies (usually non-linearly) with temperature. [1] Thermal conductivity is often measured with laser flash analysis. Alternative measurements are also established.
Thermal conduction is the diffusion of thermal energy (heat) within one material or between materials in contact. The higher temperature object has molecules with more kinetic energy; collisions between molecules distributes this kinetic energy until an object has the same kinetic energy throughout.
Thermal contact resistance is significant and may dominate for good heat conductors such as metals but can be neglected for poor heat conductors such as insulators. [2] Thermal contact conductance is an important factor in a variety of applications, largely because many physical systems contain a mechanical combination of two materials.
Compared to other metals, it is a poor conductor of heat, but a fair conductor of electricity. [ 13 ] It has a melting point of −38.83 °C [ c ] and a boiling point of 356.73 °C, [ d ] [ 14 ] [ 15 ] [ 16 ] both the lowest of any stable metal, although preliminary experiments on copernicium and flerovium have indicated that they have even ...
The gaseous and liquid nonmetals have very low densities, melting and boiling points, and are poor conductors of heat and electricity. [20] The solid nonmetals have low densities and low mechanical strength (being either hard and brittle, or soft and crumbly), [ 21 ] and a wide range of electrical conductivity.
The process of heat transfer from one place to another place without the movement of particles is called conduction, such as when placing a hand on a cold glass of water—heat is conducted from the warm skin to the cold glass, but if the hand is held a few inches from the glass, little conduction would occur since air is a poor conductor of heat.
Mercury is a liquid, heavy, silvery-white metal. It is the only common liquid metal at ordinary temperatures, and as compared to other metals, it is a poor conductor of heat, but a fair conductor of electricity. [12] The table below is a summary of the key physical properties of the group 12 elements.