What is the chemical symbol and atomic number for gold, and what is its Latin origin?

Gold is a chemical element with the symbol Au, derived from the Latin word *aurum*, and its atomic number is 79. This symbol and name reflect gold's historical significance and its Latin root, *aurum*, meaning gold.

Describe the fundamental physical properties of pure gold.

In its pure form, gold is a bright, metallic yellow metal that is dense, soft, malleable, and ductile. These properties make it easy to shape and work with, contributing to its use in jewelry and art throughout history.

How does gold's reactivity compare to other elements, and what is its classification in the periodic table?

Gold is classified as a transition metal, specifically a group 11 element and a noble metal, known for being one of the least reactive chemical elements. It ranks second only to platinum in terms of low reactivity, meaning it does not easily undergo chemical reactions.

Under standard conditions, what is the state of gold, and how does it typically occur in nature?

Under standard temperature and pressure conditions, gold is a solid. It is commonly found in nature as a free element, appearing in rocks and veins, as nuggets or grains, and in alluvial deposits, often alongside silver or other metals.

What are the key chemical reactions gold undergoes, particularly with acids and other substances?

Gold is highly resistant to most acids, but it does dissolve in aqua regia (a mixture of nitric and hydrochloric acids), forming a soluble tetrachloroaurate anion. While insoluble in nitric acid alone, it dissolves in alkaline cyanide solutions, a property utilized in mining and electroplating, and also forms amalgam alloys with mercury.

How does the rarity of gold compare to silver and platinum?

Gold is considered a rare element, being significantly less common than silver, although it is about thirty times more abundant than platinum. Its relative scarcity contributes to its status as a precious metal.

What historical monetary policies were associated with gold, and when did the world largely abandon the gold standard?

Historically, gold was often implemented as a monetary policy through the gold standard. The world gold standard was largely abandoned for fiat currency systems following the Nixon shock measures in 1971.

Which countries were the largest gold producers in 2023, and what is the estimated total amount of gold that exists above ground?

In 2023, China was the world's largest gold producer, followed by Russia and Australia. As of 2020, approximately 201,296 tonnes of gold existed above ground, which, if consolidated, would form a cube with sides measuring about 21.7 meters.

How is the world's newly produced gold consumed, and what is gold's primary industrial application?

The world's consumption of newly produced gold is divided among jewelry (about 50%), investments (about 40%), and industry (about 10%). Its most significant industrial use is in creating corrosion-resistant electrical connectors for electronic devices due to its conductivity and resistance to degradation.

What is the etymological origin of the word "gold" and its chemical symbol "Au"?

The word "gold" originates from Proto-Germanic *gulþą, ultimately stemming from a Proto-Indo-European root *ghel- meaning "yellow, green, to shine, or gleam." The chemical symbol Au comes from the Latin word *aurum*, also meaning gold, which itself derives from a Proto-Indo-European root related to "glow" or "dawn."

How does gold's malleability compare to other metals, and what is the significance of its color?

Gold is the most malleable of all metals, capable of being beaten into extremely thin sheets or drawn into wires of single-atom width without significant hardening. Its distinctive yellow color is due to relativistic effects influencing its electron orbitals, causing plasma oscillations in the visible light spectrum, unlike most other metals which appear gray or silvery.

What are some of the colored gold alloys, and how are they created?

Different colors of gold alloys are created by mixing gold with other metals. For example, rose gold is made by adding copper, white gold uses palladium or nickel, and green gold is achieved by alloying with silver.

What is colloidal gold, and how does its color vary?

Colloidal gold consists of tiny gold particles suspended in a liquid. The color of colloidal gold varies depending on the size of these particles; smaller particles typically appear red, while larger ones appear blue.

What is the only stable isotope of gold, and how many radioisotopes have been synthesized?

Gold has only one stable isotope, ¹⁹⁷Au, which is also its only naturally occurring isotope, making gold a monoisotopic element. In addition to this stable form, at least 36 radioisotopes of gold have been synthesized, ranging in atomic mass from 169 to 205.

Which radioisotope of gold is the most stable, and what are its decay modes?

The most stable radioisotope of gold is ¹⁹⁵Au, with a half-life of 186.1 days, which decays via electron capture. Another significant radioisotope, ¹⁹⁶Au, decays primarily through electron capture but also has a minor beta-minus decay path.

How was gold first synthesized, and what is the significance of this process?

The first synthesis of gold was achieved by Japanese physicist Hantaro Nagaoka in 1924 through neutron bombardment of mercury. This marked a significant step in understanding nuclear physics, demonstrating that elements could be transmuted, although the process is not economically viable for producing gold.

What are the common oxidation states of gold in its compounds, and what are the typical structures of these compounds?

The most common oxidation states for gold in its compounds are +1 (aurous) and +3 (auric). Gold(I) compounds typically exhibit a linear structure, often with soft ligands, while Gold(III) complexes are usually square planar, reflecting the d⁸ electron configuration.

What are some of the rarer oxidation states observed for gold, and in what types of compounds do they occur?

Gold exhibits rarer oxidation states including -1, +2, and +5. The -1 oxidation state is found in aurides, such as caesium auride (CsAu), where gold acts as an anion. Gold(II) compounds often feature Au-Au bonds, and gold(V) is known in compounds like gold pentafluoride (AuF₅).

What is aurophilic bonding, and how does it relate to gold chemistry?

Aurophilic bonding describes the tendency of gold ions to interact with each other at distances shorter than typical van der Waals forces but longer than conventional covalent bonds. This interaction, comparable in strength to a hydrogen bond, plays a role in the structure and properties of certain gold compounds.

How is gold produced in the universe, and what are the primary cosmic sources?

Gold is produced in the universe through cosmic processes involving the rapid neutron capture (r-process), primarily occurring during supernova nucleosynthesis, neutron star collisions, and magnetar flares. These energetic events create elements heavier than iron, including gold.

What is the theory regarding the origin of gold found on Earth's crust and mantle?

It is theorized that due to Earth's molten state during its formation, most of the gold initially present sank into the planetary core. Therefore, the gold found in the Earth's crust and mantle is believed to have been delivered later through asteroid impacts during the Late Heavy Bombardment period, approximately 4 billion years ago.

How does native gold typically occur in geological formations?

Native gold is commonly found as very small to microscopic particles embedded within rocks, often associated with quartz or sulfide minerals like pyrite (fool's gold). These are known as lode deposits, and the metal can also be found as free flakes, grains, or larger nuggets in eroded alluvial deposits called placer deposits.

Besides occurring as a native metal, in what other mineral forms can gold be found?

Gold can be found combined with tellurium in minerals such as calaverite and sylvanite. It also occurs rarely as bismuthides, like maldonite (Au₂Bi), and antimonides, such as aurostibite (AuSb₂), as well as in rare alloys with copper, lead, and mercury.

What role might microbes play in the formation of gold deposits?

Research suggests that microbes can contribute to the formation of gold deposits by transporting and precipitating gold, leading to the collection of grains and nuggets in alluvial deposits. This biological activity can influence the distribution and concentration of gold in the Earth's crust.

How might earthquakes be related to the deposition of gold?

A study proposed that during earthquakes, water trapped within geological faults can instantly vaporize. This process, known as flashing to steam, can force dissolved substances like silica and gold out of the fluids and onto nearby surfaces, potentially contributing to gold deposition.

What concentrations of gold are found in the Earth's oceans, and have attempts to extract it been successful?

The Earth's oceans contain gold at concentrations typically measured between 50 to 150 femtomoles per liter. Despite these vast quantities, attempts to economically recover gold from seawater have historically proven unsuccessful or fraudulent, indicating the extreme difficulty and cost involved.

What are the earliest known gold artifacts, and where were they discovered?

The earliest known gold artifacts in the world were discovered in Bulgaria, dating back to the 5th millennium BC (specifically between 4600 and 4200 BC). These artifacts were found in the Varna Necropolis near the Black Sea coast and are considered among the earliest well-dated gold findings in history.

How was gold utilized in ancient Egypt and Nubia, and what evidence exists of their mining activities?

Gold artifacts appeared in ancient Egypt early in its history, with smelting techniques developing during the 4th millennium BC. Egypt and Nubia were significant gold-producing regions, evidenced by hieroglyphs describing gold as plentiful and by ancient maps, like the Turin Papyrus Map, which detailed gold mine locations and geology in Nubia.

What is the historical significance of Lydia in relation to gold and coinage?

Lydia, an ancient kingdom in Asia Minor, is significant for minting what are believed to be the world's earliest coins around 610 BC, utilizing gold sourced from the region. This marked a crucial development in the history of currency and trade.

How did the Roman Empire utilize gold extraction methods, and what were some of their major mining sites?

The Roman Empire employed advanced techniques for large-scale gold extraction, notably hydraulic mining in Hispania and Dacia. Major sites included Las Médulas in Spain, where aqueducts were used to sluice alluvial deposits, and mines in Transylvania, which were exploited using opencast methods.

What impact did Mansa Musa's pilgrimage have on the economy of Egypt?

Mansa Musa, the ruler of the Mali Empire, caused significant economic disruption in Egypt during his Hajj in 1324 due to his immense wealth and lavish spending. His distribution of vast amounts of gold led to hyperinflation, depressing the price of gold in Egypt for over a decade.

What role did gold play in the European exploration of the Americas?

European exploration of the Americas was significantly motivated by the abundant gold ornaments reported among Native American peoples, particularly in Mesoamerica and South America. This allure of gold drove expeditions and colonization efforts, with much of the gold eventually being shipped to Spain.

What is the legend of El Dorado, and how did the concept evolve over time?

El Dorado is a legendary tale originating from the Muisca people of Colombia, describing a chief who covered himself in gold dust and offered treasures to a sacred lake. This myth evolved over time, fueling European exploration in search of a mythical city or empire of gold in the Americas.

How did European colonization of West Africa relate to gold?

European exploration and colonization of West Africa were largely driven by reports of significant gold deposits in the region, which eventually became known as the "Gold Coast." The gold trade was a primary focus for European merchants from the 15th to 19th centuries, influencing regional politics and trade dynamics.

What is the historical significance of the Witwatersrand Gold Rush?

The Witwatersrand Gold Rush, triggered by the discovery of vast gold deposits in South Africa in the 1880s, led to the founding of Johannesburg. These deposits, located in the Witwatersrand basin, represent some of the largest natural gold reserves ever found, significantly impacting global gold production.

How are gold mining costs typically calculated, and what was the global mine production in 2007?

Gold mining and extraction costs are generally calculated per troy ounce. In 2007, the average cost was about $317 per troy ounce, though this can vary significantly based on mining methods and ore quality, with global mine production reaching 2,471.1 tonnes that year.

What are the primary methods used for refining gold industrially?

Gold is primarily refined industrially using the Wohlwill process, which relies on electrolysis, or the Miller process, involving chlorination in a melt. The Wohlwill process yields higher purity gold but is more complex and typically used in smaller-scale operations.

What percentage of the global gold supply is recycled, and what are the associated CO₂ emissions?

Approximately 30% of the global gold supply is recycled. In 2020, mining 1 kilogram of gold produced about 16 tonnes of CO₂ equivalent, while recycling the same amount generated 53 kilograms of CO₂ equivalent, highlighting the environmental benefits of recycling.

What are the properties and compositions of common gold alloys used in jewelry?

Pure gold is often alloyed with other metals like copper, silver, palladium, or nickel to create jewelry with varying hardness, ductility, melting points, and colors. Alloys with lower karat ratings contain higher percentages of these other metals, influencing their properties and cost.

What is the primary industrial use of gold, and why is it favored for this application?

The most significant industrial use for new gold is in the fabrication of corrosion-free electrical connectors for electronic devices. Gold is favored due to its excellent electrical conductivity, ductility, and resistance to corrosion, ensuring reliable performance, especially in demanding environments.

What role does gold play in medicine, both historically and currently?

Historically, gold and its compounds were used in medicine for various ailments, believed to have health benefits due to their rarity and perceived purity. Currently, specific gold compounds like sodium aurothiomalate and auranofin are used as anti-inflammatory agents, primarily for treating arthritis.

How is colloidal gold utilized in scientific research, particularly in microscopy?

Colloidal gold preparations are used in scientific research, notably in immunogold labeling techniques for electron microscopy. Gold nanoparticles coated with specific antibodies can act as probes to detect and locate antigens on cell surfaces, appearing as dense spots under the microscope.

What toxicity concerns are associated with gold, distinguishing between metallic gold and its compounds?

While pure metallic gold is non-toxic and approved as a food additive (E175) due to its chemical inertness, soluble gold compounds (gold salts) can be toxic to the liver and kidneys. Additionally, gold cyanide compounds are toxic due to both their gold and cyanide content, with rare instances of fatal poisoning reported.

What is the significance of gold in cuisine, and what is its E number?

Gold, in the form of gold leaf, flake, or dust, is used as a decorative ingredient in gourmet foods and drinks, carrying the E number 175. While inert and providing no nutritional value, it adds a visually luxurious element, a practice dating back to medieval Europe.

What is the significance of gold in the context of the "golden mean," "golden ratio," and "golden age"?

Gold is symbolically linked to balance and ideal proportions through concepts like the "golden mean" in ethics, representing moderation, and the "golden ratio," a mathematical proportion often associated with beauty and harmony in nature and art. The term "golden age" refers to a period of great prosperity and achievement.

How has gold been used historically as money, and what is a gold standard?

Gold has been widely used globally as money for efficient exchange and wealth storage, with standardized gold bullion coins and bars produced by mints. A gold standard is a monetary system where currency was directly linked to a specific weight of gold.

What is the significance of the "Nixon shock" in relation to gold's monetary role?

The "Nixon shock" refers to the US decision in 1971 to unilaterally suspend the convertibility of the US dollar into gold. This action effectively ended the Bretton Woods system's gold standard, leading to the widespread adoption of fiat currencies.

How has the price of gold fluctuated since the end of the Bretton Woods system?

Following the "Nixon shock" in 1971, the price of gold began to increase significantly. It experienced wide fluctuations, reaching a high of $850 per troy ounce in January 1980, then declining before rising again to exceed that high in early 2008 and reaching new records in subsequent years, though it has also seen periods of decline.

How does gold's conductivity and corrosion resistance make it valuable in electronics?

Gold's excellent electrical conductivity, combined with its resistance to corrosion and oxidation, makes it highly valuable for electrical connectors in electronic devices. This ensures reliable performance, especially in applications where failure is costly or where components are exposed to harsh environments.

What is the role of gold in the context of wedding rings?

Gold wedding rings are symbolic of eternal vows and the enduring nature of marriage. The metal's durability and resistance to tarnish are seen as reflecting the lasting commitment and perfection sought in a marital union.

How did the discovery of gold in the Witwatersrand basin influence the founding of Johannesburg?

The discovery of the exceptionally rich gold deposits in the Witwatersrand basin led directly to the establishment of Johannesburg. The ensuing gold rush attracted a massive population and spurred the rapid development of the city as a center for mining and commerce.

Gold Wiki: The Gleam of Ages: Unveiling the Essence of Gold

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Fundamental Properties

Element Profile

Gold, designated by the chemical symbol Au and atomic number 79, is a lustrous, dense, soft, malleable, and ductile transition metal. It is renowned for its exceptional resistance to corrosion and most chemical reactions, positioning it among the least reactive of all elements. Under standard conditions, gold exists in a solid state.

Physical Characteristics

Gold possesses a high melting point of 1337.33 K (1064.18 °C) and a boiling point of 3243 K (2970 °C). Its density is remarkable, measuring 19.283 g/cm³ at 20°C, making it one of the densest elements. It exhibits excellent thermal and electrical conductivity, though its color, a distinctive reddish-yellow, is attributed to relativistic effects influencing its electron orbitals.

Malleability and Ductility

Gold stands unparalleled in its malleability; it can be hammered into extremely thin sheets (gold leaf) or drawn into wires of single-atom width without significant hardening. A single gram can yield a square meter of foil, demonstrating its extraordinary capacity for deformation. This property is crucial for its use in various applications, from electronics to decorative arts.

Chemical Behavior

Inertness and Reactivity

Gold is exceptionally resistant to most acids, including nitric, sulfuric, and hydrochloric acids individually. However, it dissolves in aqua regia (a mixture of nitric and hydrochloric acids) and alkaline cyanide solutions, properties historically utilized in refining and mining. Its resistance to oxidation and corrosion makes it highly stable.

Oxidation States

The chemistry of gold is dominated by its +1 (aurous) and +3 (auric) oxidation states. Au(I) compounds, often linear, are found with soft ligands like thioethers and thiolates, exemplified by the soluble [Au(CN)₂]⁻ complex used in mining. Au(III) complexes, typically square planar, are also common. Less frequent oxidation states include -1, +2, and +5, with Au(-I) forming stable aurides due to gold's high electron affinity.

Bonding and Complexes

Gold ions exhibit a phenomenon known as aurophilicity, where they interact at distances shorter than van der Waals forces, comparable to hydrogen bonds. This interaction influences the structure and properties of various gold compounds. Furthermore, gold forms numerous cluster compounds and exhibits fractional oxidation states in specific complex structures.

Global Occurrence

Cosmic Origins

Gold's presence in the universe is a result of energetic cosmic events, primarily neutron star mergers and magnetar flares, which produce heavy elements through the r-process. These events, occurring early in cosmic history, seeded the interstellar medium with gold, which was subsequently incorporated into the dust from which our Solar System formed.

Terrestrial Distribution

On Earth, gold is primarily found in native form as nuggets or grains within rocks (lode deposits) and in alluvial deposits derived from eroded rocks. It often occurs alloyed with silver (electrum) or as mineral inclusions, notably with tellurium (gold tellurides) and pyrite ("fool's gold"). The Earth's crust and mantle are believed to have received much of their gold through asteroid impacts during the Late Heavy Bombardment.

Oceanic Presence

Gold is present in trace amounts within seawater, though concentrations are extremely low (femtomoles per liter). While early estimates were higher, modern analysis indicates levels that make direct economic recovery from seawater currently unfeasible, despite historical attempts and research into its potential extraction.

Historical Significance

Ancient Beginnings

Human interaction with gold dates back to prehistoric times, with artifacts found from as early as 40,000 BC. The earliest well-dated gold artifacts originate from the Varna Necropolis in Bulgaria (c. 4600–4200 BC). Ancient civilizations in Egypt, Mesopotamia, and the Levant utilized gold extensively for religious and ornamental purposes, developing sophisticated smelting techniques.

Empires and Economies

Gold has been a cornerstone of economies and empires throughout history. Lydian coinage, dating to the 6th century BC, marked an early use of gold in standardized currency. Roman metallurgy advanced gold extraction through hydraulic mining. The Mali Empire's wealth, exemplified by Mansa Musa's 14th-century pilgrimage, significantly impacted regional economies due to gold's abundance.

Exploration and Discovery

European exploration of the Americas was heavily driven by the pursuit of gold, particularly the rich deposits held by indigenous civilizations in Mesoamerica and South America. Legends like El Dorado fueled expeditions, while the discovery of gold in regions like West Africa (the "Gold Coast") shaped colonial trade and power dynamics.

Cultural Resonance

Symbol of Excellence

Gold consistently represents the pinnacle of achievement and value across cultures. It is awarded in prestigious competitions, from the Olympic Games to the Nobel Prize, symbolizing excellence and mastery. Its association with perfection extends to concepts like the "golden mean," "golden ratio," and the "golden age," signifying periods of peak prosperity and achievement.

Spiritual and Symbolic Meanings

Across religions, gold carries profound symbolic weight. In Christianity, it signifies divinity and purity, seen in halos and sacred objects. In Islam, its use by men is often restricted, highlighting its preciousness. Gold wedding rings symbolize eternal vows and the enduring nature of commitment, reflecting its timeless appeal and perceived incorruptibility.

Artistic and Decorative Use

From ancient artifacts and royal regalia to modern jewelry and architectural embellishments, gold has been a primary medium for artistic expression and status display. Its unique color, malleability, and resistance to tarnish have made it indispensable in crafts, decorative arts, and as a symbol of wealth and prestige throughout human history.

Extraction and Use

Global Production

Major gold-producing nations include China, Russia, and Australia. Globally, approximately 201,296 tonnes of gold exist above ground. The majority of newly produced gold is allocated to jewelry (around 50%), investment (40%), and industrial applications (10%), reflecting its multifaceted value.

Industrial Applications

Beyond its monetary and aesthetic value, gold's excellent conductivity and resistance to corrosion make it vital in electronics, particularly for corrosion-resistant electrical connectors in sensitive devices. It also serves roles in infrared shielding, colored glass production, and specialized medical treatments.

Economic Role

Historically, gold underpinned monetary systems through the gold standard. Although this system was largely abandoned in the 20th century, gold remains a significant investment asset and a hedge against economic uncertainty. Its perceived stability and intrinsic value continue to influence global financial markets.

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References

Jewellery Alloys. World Gold Council

Wiberg, Wiberg & Holleman 2001, pp. 1286â1287

Moran, William L., 1987, 1992. The Amarna Letters, pp. 43â46.

Moran, William L. 1987, 1992. The Amarna Letters. EA 245, "To the Queen Mother: Some Missing Gold Statues", pp. 84â86.

Mansa Musa. Black History Pages

Lubna Umar and Sarwet Rasul, "Critical Metaphor Analysis: Nawaz Sharif and the Myth of a Golden Time" NUML Journal of Critical Inquiry 15#2, (Dec 2017): 78â102.

Death of a river . BBC News (15 February 2000). Retrieved on 4 May 2012.

A full list of references for this article are available at the Gold Wikipedia page

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This page was generated by an Artificial Intelligence and is intended for informational and educational purposes only. The content is based on a snapshot of publicly available data from Wikipedia and may not be entirely accurate, complete, or up-to-date.

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The Gleam of Ages

💡 Dive in with Flashcard Learning! 💡

Fundamental Properties 💎

⚛️ Element Profile

🌡️ Physical Characteristics

💪 Malleability and Ductility

Chemical Behavior 🧪

🛡️ Inertness and Reactivity

⚡ Oxidation States

🔗 Bonding and Complexes

Global Occurrence 🌍

🌌 Cosmic Origins

🌍 Terrestrial Distribution

🌊 Oceanic Presence

Historical Significance ⏳

🏺 Ancient Beginnings

👑 Empires and Economies

🗺️ Exploration and Discovery

Cultural Resonance 🌟

🏅 Symbol of Excellence

💍 Spiritual and Symbolic Meanings

🎨 Artistic and Decorative Use

Extraction and Use ⛏️

🏭 Global Production

💡 Industrial Applications

💰 Economic Role

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📜 Important Notice

Dive in with Flashcard Learning!

Fundamental Properties

Element Profile

Physical Characteristics

Malleability and Ductility

Chemical Behavior

Inertness and Reactivity

Oxidation States

Bonding and Complexes

Global Occurrence

Cosmic Origins

Terrestrial Distribution

Oceanic Presence

Historical Significance

Ancient Beginnings

Empires and Economies

Exploration and Discovery

Cultural Resonance

Symbol of Excellence

Spiritual and Symbolic Meanings

Artistic and Decorative Use

Extraction and Use

Global Production

Industrial Applications

Economic Role

Teacher's Corner

True or False?

Test Your Knowledge!

Gamer's Corner

Discover other topics to study!

References

Feedback & Support

Disclaimer

Important Notice