The metal is a fair conductor of electricity, but a poor conductor of heat. Mercury has a relatively high vapour pressure and the highest volatility of any metal, vapourizing to become a colourless, odourless gas. Fortunately, mercury does not form amalgam with iron, which allows for the element to be shipped in standard iron flasks containing 76 pounds, or 34.5 kilograms, of liquid mercury. The element also combines with other metals such as tin, copper, gold and silver to form mercury alloys known as amalgams. The liquid is highly mobile and droplets combine easily due to low viscosity. Droplets of liquid mercury are shiny and silver-white with a high surface tension, appearing rounded when on flat surfaces. Mercury has a melting point of -38.9 oC, a boiling point of 356.7 oC, and is the only metal to remain in liquid form at room temperature. The element's atomic mass is 200.59 grams per mole and its specific gravity is 13.5 times that of water.
The disinfectant mercury compound thimerosal is an organomercury compound found in vaccines, tattoo inks, contact lens solutions, and cosmetics.Like cadmium, zinc and lead, mercury is a naturally occurring element known as a "heavy metal" and can be toxic to living organisms. Mercury(II) fulminate is an explosive used as a primer in firearms.
When mercury forms an amalgam with aluminum, the oxide layer that protects aluminum from oxidizing is disrupted. Mercury generally is not allowed on aircraft because it combines so readily with aluminum, a metal that is common on aircraft.Mercuric sulfide is the source of the red pigment called vermilion. It accounts for only about 0.08 parts per million (ppm) and is mainly found in the mineral cinnabar, which is mercuric sulfide. Mercury is a very rare element in the Earth's crust.Hydrargyrum comes from Greek words for "water-silver" ( hydr- means water, argyros means silver). The modern element symbol for mercury is Hg, which is the symbol for another name for mercury: hydrargyrum.