This is because Hg is an abbreviation of the Latin name of the element, which was hydrargium. With this name the Greeks were referring to the fact that mercury is a silvery liquid at room temperature, rather than a solid like other metals.
We've looked at the three types of heat transfer. Conduction and convection rely on temperature differences; radiation does, too, but with radiation the absolute temperature is important.
Thermal energy is also known as internal kinetic energy. The transfer of thermal energy from one body to another is the result of temperature variations. Heat moves along areas of higher temperature to areas of lower temperature. The three mechanisms for heat transfer include conduction, convection and radiation. Conduction takes place between solid objects, convection occurs in fluids and radiation directly transfers thermal energy from space.