Mercury is the only metal that is liquid at standard conditions. It is commonly known as quicksilver due to its beautiful, silvery white colour and metallic sheen. However, appearances can be deceptive -
Mercury is one of the metals which have been known to humans for centuries -
In our times, mercury is used, among others, as a thermometer, barometer, manometer and vacuum pump filling. Large amounts of mercury are used in a process called amalgamation to extract gold and silver (especially in deposits where ores are very fragmented; metals dissolve in mercury and form amalgams from which they are then reclaimed through mercury vaporization) as well as in alkali metal electrolysis and production of explosives.
Apart from the above applications, metallic mercury is also used:
become hazardous waste to humans and the environment only after having been used;
(mercury content in a single window may reach as much as 150 mg; a lethal dose is 1 g).