Which of the following liquids is a very good conductor of heat?

Mercury, among the options provided, is a very good conductor of heat. Mercury is a metal and possesses several properties that make it an excellent conductor of heat, including high thermal conductivity and low specific heat. These characteristics allow heat to be rapidly transmitted through mercury when compared to other liquids. Due to its metallic nature, mercury’s atoms are densely packed and can easily transfer kinetic energy between one another through collisions. This efficient transfer of thermal energy makes mercury particularly suitable for applications where heat conduction is crucial, such as in thermometers and electrical switches. Water, ether, and benzene, on the other hand, are organic compounds with lower thermal conductivity compared to mercury. Therefore, the correct answer is [A] Mercury, as it stands out as a very good conductor of heat among the given liquid options.