What is Gold? – Understanding its Definition, Properties,
and Compounds

Gold is symbolized by the “Au” on the periodic table. Au is derived from Gold’s Latin name, “Aurum.” It is a precious metal famous for its brilliant yellow color and glimmer. It is considered a worthwhile asset. Possessing Unique properties makes it more attractive and appealing.

Archaeologists discovered that early humans first used Gold over 6,000 years ago. It was initially found as an alluvial river deposit, and its natural magnificence captured the attention. Gold is also found in the Earth’s crust and oceans.  

  • The atomic number of Gold is 79 because it has 79 protons orbiting its nucleus.
  • The gold formula is Au, which is derived from its Latin name.
  • Gold is a nonreactive transition metal. In the Periodic Table, Gold exists in group 11, period 6.
  • It has 79 electrons.
  • Gold has Valency is 1.

Properties of Gold

Gold possesses some extraordinary qualities. A perfect blend of these unique properties makes Gold the mysterious metal. We are going to spill the beans and explore the secrets of Gold in this article. The following Table of Contents(TOC) is the complete description of the article.

Gold Chemical Properties

PropertyValue
Atomic Number79
SymbolAu
Atomic Weight196.9665
Melting point1,063 °C/1,945 °F
Boiling point2,966 °C/5,371 °F
Oxidation States3, 1. The states -1, +2 and +5 also exist but are rare.
First Ionizing Energy889.3(kJ/mol)
Pauling Negativity Number2.54
Specific Heat0.129 (J/g mol) at20°C
Fusion Heat 12.68(kJ/mol)
Evaporation Heat340(kJ/mol)
Debye Temperature170.00 °K
Lattice Structure Face-Centered Cubic (FCC)
Lattice Constant (Å)4.080
Specific Gravity (20°C)18.88
CAS Registry Number7440-57-5
Isotopes of Gold36 known isotopes ranging from Au-170 to Au-205
Specific Gravity19.3 at 20 °C /68 °F

Physical Properties of Gold

Color

The shiny yellow color of Gold is one of its most recognizable features. It has a bright, metallic shine, which makes it highly attractive.

Density

Gold is one of the densest metals, having a density of approximately 19.32 grams per cubic centimeter.

Malleability

Gold is a soft, flexible, and malleable metal. We can spread one ounce of Gold to around 17 square meters by hammering it into extremely thin sheets called gold leaf or drawing it into 8 Km fine wires without breaking.

Conductivity

Gold is an outstanding conductor of electricity and heat. As a good conductor, Gold is used in many devices where conductivity is necessary.

Inactivity

Gold, a stable element, is resistant to oxidation and corrosion. It’s the least reactive chemical element. Gold doesn’t react with other elements and rust over time.

Gold Compounds

Gold compounds are chemical bonds of Gold with other elements. These compounds are formed when Gold reacts with other elements under specific chemical reactions. Gold, as a pure element, is relatively nonreactive and doesn’t readily form compounds. However, under specific conditions, it can form a combination of compounds. Each compound holds its unique properties. Here are a few common gold compounds

Auric Chloride

Auric chloride (AuCl3), the most common Gold compoundis produced in a combination of Gold with hydrochloric acid (HCl) and nitric acid (HNO3). This compound is also called aqua regia. Aqua regia chemical is often used for purifying and refining Gold. Auric Chloride is also named as Gold Chloride.

Gold Cyanide 

Gold cyanide is produced by the chemical bond of Gold and sodium cyanide (NaCN). Gold Cyanide(AuCN) is an inorganic compound. This compound is widely used in a process called gold electroplating. It’s an essential component in the electronics.

Gold Sulfide

Gold sulfide (Au2S) is a combination of Gold and sulfur. This compound is not present naturally, but we can produce it in a laboratory. It has limited industrial applications.

Gold Nitrate

The chemical bonding of Gold with nitric acid composes the Gold nitrate (AuNO3). We use it, particularly in analytical chemistry.

Note: We have discussed some important compounds of Gold. There are others with different elements. These Gold compounds have unique properties and uses in various fields.

Gold Alloys

Gold alloys are chemical combinations of Gold with other metals or elements. These alloys modify the properties of Gold, such as its color, hardness, and structure. The new properties of the alloy depend on the alloying metals. Some common types of Gold alloys:

Yellow Gold

Yellow Gold is an alloy of 24 Karat pure Gold with metals like copper (Cu) and silver (Ag). Yellow Gold has a deep yellow color. Different quantities of alloying metals can produce various shades of yellow.

White Gold

White Gold is formed by combining pure Gold with nickel, platinum, and silver. A thin layer of rhodium is also used for coating the white Gold to enhance the whiteness. White Gold has a silver or white appearance. It is a preferred selection for jewelry. People like to wear white Gold chains and rings.

Rose Gold

The chemical bond of pure Gold and copper forms rose Gold. Sometimes, silver is also used for certain purposes. Rose gold has a reddish or pinkish shade, which varies depending on the percentage of copper in Gold.

Green Gold

Gold and silver together make a natural alloy called electrum. Its color differs from pale green to a yellowish shade. It can be further modified with the addition of other metals.

Composition of Gold Alloy

Gold ColourAlloy Composition
Yellow GoldGold 91.67%
Silver 5%
Copper 2%
Zinc 1.33%
Red GoldGold 75%
Copper 25%
Rose GoldGold 75%
Copper 22.25%
Silver 2.75%
Green GoldGold 75%
Silver 20%
Copper 5%
White GoldGold 75%
Platinum 10%
Nickel 10%
Zinc 5%

What is Gold Ore?

Gold ore is a rock that contains Gold in a natural form. The rocks gathered in the Gold mining process are called Gold Ore. Ores contain Gold in raw form. These Ores are extracted to form the precious metal. Gold Ores are scattered geologically. These are found in the Earth’s crust, rivers, and oceans.

Types of Gold Ore

  1. Silver-gold ore.
  2. Quartz gold ore.
  3. Blue clay gold ore.
  4. Iron oxide copper gold ore.
  5. Gold sulfide ore.
  6. Tellurium gold ore.
  7. Gold in arsenopyrite.
  8. Granite gold ore.

FAQs

Au is the Gold symbol. It is derived from the word “Aurum,” which is the Latin name of Gold,

When a Gold element is observed in a microscope, 79 protons are discovered orbiting its nucleus. Atomic Number 79 represents the number of protons; that is the reason Gold is called element 79.

Gold is an element. It is not a compound.

Gold is primarily formed at the start of the universe by massive stars’ severe heat and pressure. Nuclear fusion reactions generated this heat. It is then scattered throughout the universe, including Earth, where geological processes make it accessible for mining.

Gold electroplating, a coating process, creates a thin layer of Gold to other metals. Mostly, it is used to coat copper and silver chemically. The width of the thin layer is approximately 0.0002 inches.