Mercury - The Element

Properties

• Very dense (13.5 g/cc vs. water’s density of 1 g/cc)
• Expands and contracts evenly with changes in temperature
• High electrical conductivity
• The only heavy metal that exists as a liquid at room temperature
• Alloys with other metals (e.g. silver, gold, copper, nickel) to form amalgams
• Easily vaporizes
• Toxic to living organisms

Forms

Hg (mercury zero)

• The elemental form of mercury, appearing as a silver liquid when contained at room temperature
• Easily volatilizes in to the atmosphere and remains there from three months to two years
• Not very water soluble, thus it does not readily wash out of the atmosphere during rainfall
• Removed from the atmosphere very slowly after converting mostly to HgII

Hg (II) (mercury two)

• Ions known as mercury salts
• Water soluble and easily attached to particles
• Readily washes out of the atmosphere

MeHg (methylmercury)

• The organic form of mercury
• Volatile
• Very water soluble
• Readily washes out of the atmosphere
• Bioaccumulative

Transport

Mercury is released into the air, water, and land and it cycles between them due to its ability to change forms. Mercury gets into the soil through natural breakdown of rocks, disposal of mercury in landfills, and atmospheric deposition. It enters the water through runoff, atmospheric deposition, and when mercury from products is poured down the drain. Mercury is released to the atmosphere through coal-fired utility, chlor-alkali plant, and incinerator emissions, as well as evaporation from water and land. Once mercury enters this cycle, it can remain in the environment for years as it accumulates. It can not be removed, but it can be prevented from ever entering the environment.

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