South Africa used to be the largest supplier of the world's gold, but today China and Australia produce the most gold.That's bigger than a football field! That same ounce can form a wire nearly 100 kilometers long. A single ounce of gold can be pounded into a sheet 300 feet wide by 300 feet long.Gold has only one naturally occurring stable isotope: gold-197. The symbol Au comes from the Latin word for gold, "aurum." Gold gets its name from the Anglo-Saxon word "geolo" for yellow. It has long been a substance of value and wealth. Civilizations such as Ancient Egypt used gold over 5000 years ago. Gold has been known about since ancient times. Other applications for gold include heat shielding, dental work, cancer treatment, and decoration such as gold thread and gold plating. Many electrical contacts and connectors are plated with gold for protection and reliability. Gold is used a lot in the electronics industry because of its good electrical conductivity and resistance to corrosion. Generally gold is alloyed with other metals such as copper or silver in order to make it harder and more durable. Pure gold is called 24 karat gold and it is very soft. When gold is used as jewelry or for coins, it is generally not pure gold. Gold is also considered an important and reliable investment. Today it is still used for jewelry and for some collector's edition coins. Gold has been used for thousands of years to make jewelry and coins. However, the process for retrieving gold from ocean water costs more than the gold itself. It can be found in veins underground or in small fragments in sandy riverbeds. Because it doesn't react with very many other elements, it is often found in its native form in the Earth's crust or mixed with other metals like silver. Gold is an extremely rare element on Earth. It is also one of the most resistant metals to corrosion and rust when exposed to air and water. It is an excellent conductor of electricity and heat. Gold is more than just a beautiful metal. It is also one of the most ductile metals and can be easily stretched into a long wire. Gold is the most malleable of the metals meaning that it can be pounded into a very thin sheet. It is very dense and heavy, but also fairly soft. Under standard conditions gold is a shiny yellow metal. Gold atoms have 79 electrons and 79 protons with 118 neutrons in the most abundant isotope. Gold is the third element in the eleventh column of the periodic table. Discovered by: Known about since ancient times.Modern nuclear chemists have found methods to accomplish this historic task. Transmuting lead into gold was one of the major goals of the alchemists.Elemental gold metal is considered non-toxic and occasionally used as a food additive.The acid aqua regia is used to dissolve gold. Jewelry gold is made of many different gold alloys. Today, gold in jewelry is not 'pure' gold. Gold has been used as jewelry since prehistoric times.Noble metal is an alchemical term for metals that do not corrode under normal conditions. (Cesium and rubidium can form auride compounds) Compounds containing gold in the -1 oxidation state are called aurides.The gold ion in the +3 oxidation state (Au(III) 3+) is called the auric ion.The gold ion in the +1 oxidation state (Au(I) +) is called the aurous ion.The melting point of gold is an assigned value, which serves as a calibration point for the International Temperature Scale and International Practical Temperature Scale.One ounce of gold can be beaten out to 300 ft 2 or stretched into a wire 2000 kilometers long (1 μm thick). Gold is the most malleable and ductile metal.Gold is one of the few elements that can be found in its native state.
0 Comments
Leave a Reply. |