Mercury
Element Name: Mercury
Atomic Number: 80
Atomic Mass: 200.592
Atomic Symbol: Hg
Melting Point: -38.829° C
Boiling Point: 356.73° C
Mercury is a shiny, fast-flowing metal. This makes mercury unique since it is the only pure metal to be a liquid at room temperature, with the possible exception of gallium which can melt in your hand (rubidium and cesium too, although they’re much more hazardous). Mercury also happens to be extremely dense, around 14 times as dense as water. It’s a poor conductor of heat, but a decent conductor of electricity. Like many heavy metals, mercury is extremely toxic. In humans this manifests as a slew of symptoms, the most notable ones involve peripheral neuropathy (fabricated sensations of pain, itching, burning, or insects crawling on one’s skin). Mercury is stable in its elemental form, but will react with strong acids and hydrogen sulfide. It also has a unique ability to dissolve other metals, creating amalgams. It has 34 known isotopes, 7 of which are naturally found in the crust.
Interesting Facts:
Mercury’s atomic symbol, Hg, comes from the Greek hydrargyrum, meaning “liquid silver”. In ancient China mercury was thought to be a medicine that granted immortality, and many of the first emperors consumed it. Qin Shi Huang, the first emperor, was buried in a great tomb that supposedly mirrored a map of China where all the rivers were replaced with mercury. In the early 20th century mercury was thought to be a cure for syphilis, but mercury’s toxicity often caused symptoms that were accredited to syphilis. Felt hats were also made by processes using mercury well into the 19th century, causing many hatters to contract mercury poisoning. It’s from this that the term “mad as a hatter” sprouted, and the Mad Hatter character from Alice in Wonderland may be based off of this. Mercury tends to bioaccumulate in fish. This means that fish high up in the food chain will have a lot of mercury in their system, and in turn will have mercury in their flesh. Tuna and shark must be eaten with moderation if mercury poison is a concern.
Sources:
Mercury is very rare, and only occurs in around 80 parts per billion in the earth’s crust. It is sometimes found in its elemental form, but more commonly it’s found in cinnabar, corderoite, and livingstonite. China and Kyrgyzstan were the most notable producers of mercury as of 2005. Because of its toxicity, many government safety groups heavily regulate mercury mining and consumption.
Industrial Uses:
In recent years mercury has lost popularity. The EU has placed strict regulation on many of mercury’s old uses, often replacing it with more expensive (but safer) alternatives like galinstan. A notable use still in practice is dental amalgam (the silver fillings used to replace the matter lost in a cavity). Thimerosal was once used in vaccines as a preservative, but this practice has stopped. Thermometers and barometers also have stopped being popular, and since 2003 the sale of mercury thermometers has been limited to prescription only. Liquid mirror telescopes use mercury for its reflective properties. These telescopes are much cheaper than their counterparts, but cannot be moved easily and must always point straight up. One industry where mercury is still alive and well is lighting. A “neon sign” may have mercury in it, and mercury vapors are still used in fluorescent lamps.
References:
“Mercury.” Chemicool Periodic Table. Chemicool.com, 9 Oct. 2012. Web. 26 July
2016.
“Mercury.” Wikipedia. Wikimedia Foundation, n.d. Web. 26 July 2016.
“Facts About Mercury.” Livescience. Livescience.com, 11 Dec. 2013. Web. 26 July 2016.
Gray, Theodore W., and Nick Mann. The Elements: A Visual Exploration of Every
Known Atom in the Universe. New York: Black Dog & Leventhal, 2009. Print.
Aldersey-Williams, Hugh. Periodic Tales: A Cultural History of the Elements, from
Arsenic to Zinc. New York: Ecco, 2011. Print.