what is gold

Gold
Chemical Element
Gold is a chemical element with the symbol Au and atomic number 79. It is a dense, soft, malleable, and ductile metal with a bright yellow color and luster that is considered attractive, which is maintained without tarnishing in air or water. Wikipedia
Symbol: Au
Melting point: 1,064 °C
Electron configuration: [Xe] 4f14 5d10 6s1
Atomic number: 79
Boiling point: 2,856 °C
Atomic mass: 196.96657 ± 0.000004 u


gold

A yellow precious metal, the chemical element of atomic number 79, valued esp. for use in jewelry and decoration, and to guarantee the...
An alloy of this: "9-carat gold".

Gold is the most malleable of all metals; a single gram can be beaten into a sheet of 1 square meter, or an ounce into 300 square feet. Gold leaf can be beaten thin enough to become transparent. The transmitted light appears greenish blue, because gold strongly reflects yellow and red.[20] Such semi-transparent sheets also strongly reflect infrared light, making them useful as infrared (radiant heat) shields in visors of heat-resistant suits, and in sun-visors for spacesuits.[21]

Gold readily creates alloys with many other metals. These alloys can be produced to modify the hardness and other metallurgical properties, to control melting point or to create exotic colors.[22] Gold is a good conductor of heat and electricity and reflects infrared radiation strongly. Chemically, it is unaffected by air, moisture and most corrosive reagents, and is therefore well suited for use in coins and jewelry and as a protective coating on other, more reactive metals. However, it is not chemically inert. Gold is almost insoluble, but can be dissolved in aqua regia.
Common oxidation states of gold include +1 (gold(I) or aurous compounds) and +3 (gold(III) or auric compounds). Gold ions in solution are readily reduced and precipitated as metal by adding any other metal as the reducing agent. The added metal is oxidized and dissolves, allowing the gold to be displaced from solution and be recovered as a solid precipitate.
In addition, gold is very dense, a cubic meter weighing 19,300 kg. By comparison, the density of lead is 11,340 kg/m3, and that of the densest element, osmium, is 22,610 kg/m3.