Metal Report: Mercury (Hg)

METAL REPORT:  Charlie, Georgie, Ben

1. The production cycle for mercury include:
- degrassing of mercury from rock, soils, and surface waters, or emissions from volcanoes and from human activities.
- movement in gaseous form through the atmosphere
- deposition of mercury on lad and surface waters
- conversion of the element onto insoluble mercury sulfide
- predipititation or bioconversion into more volatile or  soluble forms such as methylmercury
- reentry into the atmosphere or bioaccumulations in food chains

Consumption of mercury:
The consumption of mercury occur in people in the U.S. that are mainly exposed to methylmercury, an organic compound. When people eat fish and shellfish that contain mercury, almost all people have at least trace amounts of methylmercury in their tissues, reflecting methylmercury’s widespread presence in the environment and people’s exposure through the consumption of fish and shellfish.

History of mercury:
Mercury was named after the Roman god Mercury, as well as the planet “Mercury.” Mercury was known to ancient Chinese and Hindus before 2000 BC and was found in tubes in Egyptian tombs dated from 1500 BC. The Greeks used mercury for ointments and the Romans used mercury in cosmetics which sometimes deformed the face. Mercury forms useful compounds with other elements. For example, mercuric chloride (HgCl₂) is a very poisonous salt and was once used to disinfect wounds. Mercury is not usually found free in nature and is primarily obtained from the mineral cinnabar (HgS). Hg is a chemical symbol that comes from hydrargyrum, which is a compound word meaning "water-silver."

Uses for mercury:
Three current uses for metals are in thermometers, barometers, and dental amalgams.


2. Mercury's properties (chemical and physical):

3. Mercury is used in thermometers because it has a large thermal expansion. Mercury is also used in Barometers due to its high density. And finally, mercury is used to be used as a component for Dental Amalgams because people use to use copper and tin for fillings, but when they fixed it with mercury they were able to get greater supply, which made it cheaper. The only use for Mercury that was replaced in the past few years was the Dental Amalgams. Dentists have found more efficient ways to make tooth fillings and prevent cavities.


4. Estimated Crustal Abundance: 8.5×10-2 milligrams per kilogram. Estimated Oceanic Abundance: 3×10-5 milligrams per liter. Mercury rarely occurs free in nature, but can be found in ores, mainly mercury sulfide (cinnabar, HgS). The metal is extracted by roasting cinnabar in an air current. The resulting mercury vapor is condensed to collect the liquid metal. Mercury's abundance in Earth's crust is 85 parts per billion by weight, 9 parts per billion by moles. Mercury (Hg) is an element and a natural part of our universe. It has been identified on the sun and found in meteorites and moon rocks. On the Earth, natural deposits of mercury are generally found as cinnabar (HgS), a vermilion red ore that is up to 86% mercury. Cinnabar deposits are relatively rare, and are known to occur in association with hot springs and recent volcanic rocks, suggesting a mantle or deep crustal origin. Mercury is 67th in natural abundance in crustal rocks, with concentrations of 0.2 parts per million (ppm) found in granite and less than 0.1 ppm in other crustal rocks.