The metallic element referred to as gold is one of the first known metals. Ownership of this attractive bright yellow metal has been a symbol of wealth for thousands of years. During the Middle Ages, an entire science called alchemy grew up around the effort to create gold by artificial means.
Modern scientists have completed their goal in making some of the alchemists dreams come true. Gold can now be extracted from seawater, and the particle accelerator can make gold from lead and mercury. It can also create an unstable form of gold from platinum and iridium, both of which are a higher value than gold. But all the gold produced commercially still comes from the earth. The mining of this rare metal has become an important industry, which is carefully supervised by the governments of all gold-producing countries.
Gold has been valuable throughout the ages mainly because it is scarce.
It can be formed into any shape desired, and after it is shaped, its resistance to rust and other chemical modifiers from the air prevents it from tarnishing. When gold is to be made into a solid object, such as a piece of jewelry, it must be combined with some other metal. Such a substance is known as alloy. Gold alloys are measured by carats, which are equal to one twenty-fourth part. So, 24 carat gold would be pure gold, while eighteen carat gold is 18 parts pure gold, to 6 parts alloy.
Pure gold melts at 1064.43 Degrees Celsius and boils at 2807 Degrees Celsius. It is located in group I of the table of chemical elements with an atomic weight of 196.967 and an atomic number of 79. It can be dissolved in a mixture of various hydrochloric and nitric acids.
In conclusion, gold is an...