Gold

Element Name: Gold
Atomic Number: 79
Atomic Mass: 196.966569
Atomic Symbol: Au
Melting Point: 1064.18° C
Boiling Point: 2850° C

Gold is an extremely ductile and malleable metal with a characteristic color. It’s a good conductor of heat and electricity while also being able to deflect infrared radiation. Gold’s most recognizable property is its ability to remain unbounded in its elemental form and resist corrosion. Gold will dissolve if placed in aqua regia (a mix of nitric and hydrochloric acids) or if amalgamated with mercury, but otherwise will remain inert for thousands of years assuming it is not exposed to extreme conditions. When reacting gold will either be in the -1, +2, or +5 oxidation state. There is only one stable isotope of gold, 197Au, which makes up all of the naturally found gold on earth. 36 radioisotopes of gold exist, ranging from an atomic mass of 169 to 205. The word “Gold” comes from the Anglo-Saxon word for “geolo” (meaning yellow) and the Sanskrit word jval meaning “to shine”.

Interesting Facts:

Gold’s atomic symbol comes from the Latin word for gold, Aurum. The first use of gold traces back 6200 years ago in Bulgaria where several artifacts were discovered. Alchemists believed that gold was a mix of mercury in the highest purity mixed with sulfur of the highest purity. They are partially correct in that a reactor can turn certain types of mercury into gold, just not in an economically viable way. Gold’s purity is often measured in the carat system, where 24 carat pure gold and 0 carat has no gold content. The gold standard was in place from ancient times until 1975. This standard meant that every currency in circulation had some corresponding gold in a treasury to guarantee its value. Gold is inert and non-toxic, a fact that allows it to be used as decoration in gourmet foods, usually in a form of a gold flake. Adjusting for inflation, the highest price gold has seen on the market is $2584 in 1980. The absolute highest selling point for gold was $1913.50 in August of 2011.

Sources:

In 2014 there was 183,600 tons of gold total above the ground – enough to make a cube of roughly 60 feet on edge. Gold can be found in its elemental form, alloyed with other metals, or in minerals. Commonly gold can be found in rivers near larger deposits. In 2014, 2990 tons of gold were mined, the major suppliers being China, Australia, U.S., Russia, and Peru. Some investigation has revealed that seawater contains trace amounts of gold that would amount to nearly 15,000 tons of gold, but no economically viable way of processing that much water has been found. Typical extraction methods include using the environmentally unfriendly process of gold cyanization to dissolve the surrounding minerals but leave the gold intact. In 2013 a new method was discovered that relies on the starch alpha-Cyclodextrin which can precipitate gold out of a sample at 97% purity.

Industrial Uses:

Around 50% of gold produced is used in jewelry, 40% in investments, and only 10% in industrial application. Beginning with industry, gold is mainly used in electronics. As stated prior, gold is very resistant to corrosion and conductive which makes it a great choice for a connector in devices like cellphones. It is sometimes not necessary to include gold in these devices, but in the case of devices with high failure costs (such are spacecraft) it is used commonly. In more specific uses, gold can be used in photography, protective coating on objects in space, and in commercial chemistry. Gold compounds are also used in medicine to a limited extent as an anti-inflammatory or in radiation therapy. The 50% of gold used in jewelry might itself be considered an industry, but it is a more artisanal use. Gold is desired for its beauty and ability to maintain its shine. When alloyed with other metals (and reducing the carat of the gold) it can be made much more durable and be imbued with more exotic colors.

References:

“Gold.” Chemicool Periodic Table. Chemicool.com, 17 Oct. 2012. Web. 26 July
2016.
“Gold.” Wikipedia. Wikimedia Foundation, n.d. Web. 26 July 2016.
“Facts About Gold.” Livescience. Livescience.com, 15 Apr. 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.