Throughout history, people have cherished gold, fought for it, and even died for it. The physical and chemical properties of gold make it special. First, its intrinsic beauty and rarity make it precious. Second, it is soft and can be easily formed into jewelry, coins, and other objects. Third, it is one of
the least active metals . It is not oxidized in air and does not react with water , with basic solutions, or with most acidic solutions.Many of the early studies on gold arose from alchemy, in which people attempted to turn cheap metals, such as lead, into gold. Alchemists discovered that gold can be dissolved in a 3:1 mixture of concentrated hydrochloric and nitric acids, known as "aqua regia"
(“royal water”). The action of the nitric acid on gold is similar to that on copper . All the gold ever mined would fit in a cube 21 m on a side andweighing about 1.6 × 10^8 kg. More than 90% of this amount has been produced since the 1848 California gold rush. Annual worldwide production of gold is about 2.4 × 10^6 kg. By contrast 16,000 times more aluminum, over 3.97 × 10^10 kg, are produced annually. Roughly three-quarters of gold production goes to make jewellry, where it is often alloyed with other metals. Approximately 12% of gold production is used to meet a variety of industrial applications, most notably in electronic devices where its excellent conductivity and corrosion resistance make it a valuable component. A typical touch-tone telephone contains 33 gold-plated contacts.Gold is also used in computers and other microelectronic devices where fine gold wire is used to link components. Because of its resistance to corrosion, gold is an ideal metal for dental crowns and caps, which accounts for about of the annual use of the element. The pure metal is too soft to use in dentistry, so it is combined with other metals to form alloys.
Pic Source:pixabay.com,en.wikimedia.org, commons.wikimedia.org
the least active metals . It is not oxidized in air and does not react with water , with basic solutions, or with most acidic solutions.Many of the early studies on gold arose from alchemy, in which people attempted to turn cheap metals, such as lead, into gold. Alchemists discovered that gold can be dissolved in a 3:1 mixture of concentrated hydrochloric and nitric acids, known as "aqua regia"
(“royal water”). The action of the nitric acid on gold is similar to that on copper . All the gold ever mined would fit in a cube 21 m on a side andweighing about 1.6 × 10^8 kg. More than 90% of this amount has been produced since the 1848 California gold rush. Annual worldwide production of gold is about 2.4 × 10^6 kg. By contrast 16,000 times more aluminum, over 3.97 × 10^10 kg, are produced annually. Roughly three-quarters of gold production goes to make jewellry, where it is often alloyed with other metals. Approximately 12% of gold production is used to meet a variety of industrial applications, most notably in electronic devices where its excellent conductivity and corrosion resistance make it a valuable component. A typical touch-tone telephone contains 33 gold-plated contacts.Gold is also used in computers and other microelectronic devices where fine gold wire is used to link components. Because of its resistance to corrosion, gold is an ideal metal for dental crowns and caps, which accounts for about of the annual use of the element. The pure metal is too soft to use in dentistry, so it is combined with other metals to form alloys.Pic Source:pixabay.com,en.wikimedia.org, commons.wikimedia.org
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