Mercury
By
TABLE OF CONTENTS
Table of Contents ............................................................................................................................ 1
Introduction ..................................................................................................................................... 1
History and discovery ..................................................................................................................... 2
Data ................................................................................................................................................. 2
Uses ................................................................................................................................................. 3
Harmful effects ............................................................................................................................... 4
Interesting facts ............................................................................................................................... 5
Conclusion ...................................................................................................................................... 6
References ....................................................................................................................................... 6
INTRODUCTION
Transition metals are a very important “element” in chemistry. Transition metals are the
set of metallic elements in the central block of the periodic table that have valence electrons that
can participate in the formation of chemical bonds in two shells instead of only one. Transition
metals are like main group metals in many ways, they look like metals, they are malleable and
ductile, they conduct heat and electricity, and they form positive ions, but they are also very
different. The transition metals are more electronegative, they are more likely than main group
metals to form complexes and they easily form stable compounds with neutral molecules. There
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is some controversy about the classification of transition-metal elements on the right side of the
table zinc, cadmium, and mercury (zinc group elements) because they exhibit few of the
characteristics of the other transition elements. One of the most unique and interesting of these is
mercury.
HISTORY AND DISCOVERY
Mercury is a liquid, silvery meatal and is one of the elements that has been known since
ancient times. Its unique property of being a liquid at room temperature has attracted attention
for centuries. It is the only metal that has this property. It is not known who discovered it, but it
was used by the Chinese, Hindus and even found in ancient Egyptian tombs as far back as 1500
BC. Aristotle was documented as calling it ‘hydro-argyros’ which translates as liquid-silver or
quicksilver. The Romans modified the Greek name to Hydrargyrum, therefore the chemical
symbol for mercury is Hg. The modern name came from alchemists who observed the element’s
rapid liquid flow and compared it to the fastest moving planet, Mercury that was named after the
Roman messenger of the gods. The Romans operated mercury mines with criminals and slaves,
the prisoners had short life span due to poisoning and it has been said that mercury could be
collected from their sweat. Alchemists used to believe that when combined with other metals
mercury could be turned into gold when actually mercury dissolves gold.
DATA
Mercury has 80 protons in the nucleus which makes its atomic number 80. The average
mass of the atom, or Atomic weight, is 200.59, and it has a density of 13.5336 grams per cubic
centimeter. Mercury has a melting point of -37.89°F (-38.83°C) and a boiling point of 674.1°F
(356.7°C), this is closer together than for any other metals which is why it’s a liquid a room
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temperature. It can form 34 atoms with a different number of neutrons, or isotopes, 7 of which
are stable isotopes. The most abundant naturally forming isotope is 202Hg is at 29.9%.
Abundance in the earth’s crust is 85 parts per billion by weight, and abundance solar system is
20 parts per billion by weight. The cost of pure Mercury is about $48 per 100g. Finding it in its
native state is rare in nature. It is primarily obtained from the mineral cinnabar (HgS), it must go
through a heating and condensing process to be obtained. Mercury may also sometimes be found
with Silver (Au). It tends to be found in high concentrations in regions where there are hot
springs or volcanos. Trace amounts of mercury also occur naturally in fish and other seafood. All
food we eat actually has small amounts of mercury which we can cope with easily, a daily intake
of less than 0.01 milligrams. China and Kyrgyzstan are the main producers of mercury.
USES
Mercury has been used as far back as 30,000 years ago in paint used on cave walls. It was
also put in bowls and used as mirrors in spiritual ceremonies. Chinese alchemist, Ko-Hung tried
smearing mercury on people's feet to see if it would make them able walk on water. He also
placed it on doorsteps to keep thieves away. He even tried combining it with raspberry juice to
try to make older men able to have more children. Ancient Chinese drank mercury cocktails
thinking it was the key to eternal life and well-being. Qin Shi Huang, Chinas first emperor, is
said to have believed so powerfully in the magical properties of Mercury that he died seeking
immortality by coughing out mercury. Mercury compounds have been used in all types of
traditional medicine as a diuretic, topical disinfectant, antidepressants, and a laxative. It has even
been used as a treatment for syphilis although its toxic effects were sometimes confused with
that of the syphilis. Romans were known to use it in cosmetics which often caused disfiguration.
Even some modern mascaras contain mercury compounds. It was used in the production of
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fishing lures and even was used for lens rotation in lighthouses. One of its main uses has been in
the mining of silver and gold.
Today Mercury is still used in many products, although its use is diminishing and
carefully regulated. It is used in thermometers because of its high rate of linear thermal
expansion and in barometers and manometers because of its high density. Due to its ability to
form many alloys, it is still used as an amalgam in dentistry. It is used in the production of
batteries, electrical components like switches, and light bulbs. It is even used in the production of
some vaccines. No one knows exactly what the future uses of Mercury will be, but even with its
toxicity, I’m sure that due to its unique property’s, there will be many advances in the safe use of
Mercury.
HARMFUL EFFECTS
Mercury is toxic and can enter the body in many ways including the respiratory tract, the
digestive tract and directly through the skin. It can produce harmful effects on the nervous,
digestive and immune systems, lungs and kidneys, and can be fatal. Neurological and behavioral
disorders have been observed after exposure. Mercury mainly causes health effects when inhaled
as a vapor. Symptom of prolonged exposures include tremors, emotional changes (like mood
swings, irritability, nervousness, excessive shyness), insomnia, neuromuscular changes (like
weakness, muscle atrophy, twitching), headaches, disturbances in sensations, changes in nerve
responses, poor performance on tests of mental function. Higher exposures may also cause harm
to kidneys, respiratory failure and death. Infants in the womb can be exposed when their mothers
eat fish and shellfish, therefore pregnant women are advised against eating fish. This exposure
can adversely affect unborn infants' growing brains and nervous systems which are more
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vulnerable than the brains and nervous systems of adults. Children exposed to mercury while
they are in the womb can have effects to their cognitive thinking, memory, attention, language,
fine motor skills, and visual spatial skills.
Mercury becomes a problem for the environment when it is naturally released from rock
and ends up in the water and atmosphere. This can be caused by volcanoes and forest fires.
Human activities are responsible for a considerable amount of the mercury that is released into
the environment. The burning of coal, oil and wood as fuel can cause mercury to become
airborne and this airborne mercury can fall to the ground. Since mercury occurs naturally in coal
and other fossil fuels, when people burn these fuels for energy, the mercury becomes airborne
and goes into the atmosphere. In the United States, power plants that burn coal to create
electricity account for about 42 percent of all manmade mercury emissions. Mercury pollution is
now identified as a global problem and awareness has been raised on an international level.
INTERESTING FACTS
Mercury is not allowed on aircraft because it combines so easily with aluminum and it is
used to make many aircraft, the oxide layer that protects aluminum from oxidizing is disturbed
and causes the aluminum to corrode like iron rusts. Mercury does not react with most acids.
Mercury is a relatively poor conductor of heat. Most metals are excellent thermal conductors. It
is a mild electrical conductor. Mercury usually exhibits a +1 or +2 oxidation state, but it can
sometimes have a +4-oxidation state. The electron configuration causes mercury to behave like a
noble gas and forms weak chemical bonds with other elements. It forms amalgams with all the
other metals, except for iron. That is why iron is used to make containers to hold and transport
mercury.
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CONCLUSION
While there are many interesting elements in the world, mercury is without a doubt one
of the most interesting. Its early discovery and unique properties have made it the subject of
many aspects of history in many cultures. Its unique properties also make it useful in the
production of many different products. There is enough evidence of significant adverse impacts
of mercury and its compounds on a global scale. There should be global action to reduce the
risks to human health and the environment arising from mercury releases. Even though its
toxicity has diminished its use in many areas, its inevitable that there will be future uses and
discoveries of this beautiful, memorizing, and interesting transition metal element.
REFERENCES
Royal Society of Chemistry. (2018, Nov 30). Mercury. Retrieved from Periodic table:
http://www.rsc.org/periodic-table/element/80/mercury
Thomas Jefferson National Accelerator Facility - Office of Science Education. (2018, Nov 24).
It's Elemental. Retrieved from Jefferson Lab:
https://education.jlab.org/itselemental/ele080.html
"Mercury." Chemicool Periodic Table. Chemicool.com. 17 Oct. 2012. Web. (2018, Nov 14)
<https://www.chemicool.com/elements/mercury.html>.
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