1. Less than 50% of the world’s gold is still underneath the ground
2. Gold is the only metal that is yellow or "golden". Other metals may develop a yellowish color, but only after they have oxidized or reacted with other chemicals.
3. Nearly all of the gold on Earth came from meteorites that bombarded the planet over 200 million years after it formed.
4. The element symbol for gold is Au. The symbol comes from the old Latin name for gold, aurum, which means "shining dawn" or "glow of sunrise". The word "gold" comes from the Germanic languages, originating from the Proto-Germanic gulþ and Proto-Indo-European ghel, meaning "yellow/green". The pure element has been known since ancient times.
5. Gold is extremely ductile. A single ounce of gold (about 28 grams) can be stretched into a gold thread 5 miles (8 kilometers) long. Gold threads can even be used as embroidery thread.
6. Malleability is a measure of how easily a material can be hammered into thin sheets. Gold is the most malleable element. A single ounce of gold can be beaten out into a sheet that is 300 square feet. A sheet of gold can be made thin enough to be transparent. Very thin sheets of gold may appear greenish blue because gold strongly reflects red and yellow.
7. Although gold is a heavy, dense metal, it is generally considered non-toxic. Gold metal flakes may be eaten in foods or drinks.
8. 24 karat gold is pure elemental gold. 18 karat gold is 75% pure gold. 14 karat gold is 58.5% pure gold, and 10 karat gold is 41.7% pure gold. The remaining portion of the metal usually is silver, but may consist of other metals or a combination of metals, such as platinum, copper, palladium, zinc, nickel, iron, and cadmium.
9. Gold is noble metal. It is relatively unreactive and resists degradation by air, moisture, or acidic conditions. While acids dissolve most metals, a special mixture of acids called aqua regia is used to dissolve gold.
10. Gold has many uses, aside from its monetary and symbolic value. Among other applications, it is used in electronics, electrical wiring, dentistry, electronics, medicine, radiation shielding, and to color glass.
11. High purity metallic gold is odorless and tasteless. This makes sense, since the metal is unreactive. Metal ions are what confer flavor and odor to metallic elements and compounds.
12. The world’s largest gold bar has a mass of 250 kg’s.
Gold is most commonly found in… Jewelry: rings, bracelets, necklaces, earrings, broaches.
Gold is highly conductive to electricity, and has been used for electrical wiring in some high energy applications. For example, gold electrical wires were used during some of the Manhattan Project's atomic experiments, but large high current silver wires were used in the cauldron isotope separator magnets in the project.
Though gold is attacked by free chlorine, its good conductivity and general resistance to oxidation and corrosion in other environments (including resistance to non-chlorinated acids) has led to its widespread industrial use in the electronic era as a thin layer coating electrical connectors, thereby ensuring good connection. For example, gold is used in the connectors of the more expensive electronics cables, such as audio, video and USB cables. The benefit of using gold over other connector metals such as tin in these applications has been debated; gold connectors are often criticized by audio-visual experts as unnecessary for most consumers and seen as simply a marketing ploy. However, the use of gold in other applications in electronic sliding contacts in highly humid or corrosive atmospheres, and in use for contacts with a very high failure cost (certain computers, communications equipment, spacecraft, jet aircraft engines) remains very common.
Besides sliding electrical contacts, gold is also used in electrical contacts because of its resistance to corrosion, electrical conductivity, ductility and lack of…