Group 11 element
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4
Period 4 element
A period 4 element is one of the chemical elements in the fourth row of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour...

5
Period 5 element
A period 5 element is one of the chemical elements in the fifth row of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour...

6
Period 6 element
A period 6 element is one of the chemical elements in the sixth row of the periodic table of the elements, including the lanthanides...

7
Period 7 element
A period 7 element is one of the chemical elements in the seventh row of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical...

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Legend
Transition metal
Primordial element
Synthetic

A Group 11 element is one in the series of elements
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...

 in group 11
Periodic table group
In chemistry, a group is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table, including the d-block elements, but excluding the f-block elements....

 (IUPAC style) in the periodic table
Periodic table
The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...

, consisting of transition metal
Transition metal
The term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...

s which are the traditional coinage metals of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 (Cu), silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 (Ag), and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

  (Au). Roentgenium
Roentgenium
Roentgenium is a synthetic radioactive chemical element with the symbol Rg and atomic number 111. It is placed as the heaviest member of the group 11 elements, although a sufficiently stable isotope has not yet been produced in a sufficient amount that would confirm this position as a heavier...

 (Rg) belongs to this group of elements based on its electronic configuration
Electron configuration
In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure...

, but it is a short-lived transactinide with a 22.8 seconds half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

 that has only been observed in laboratory conditions. Although at various times societies have used other metals in coinage including aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

, lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

, nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...

, stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....

, tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

, and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

, the name "coinage metals" is used to highlight the special physio-chemical properties that make this series of metals uniquely well suited for monetary purposes. These properties include ease of identification, resistance to tarnish, extreme difficulty in counterfeiting, durability, fungibility and a reliable store of value unmatched by any other metals known.

History

All the elements of the group except Roentgenium have been known since prehistoric times, as all of them occur in metallic form in nature and no extraction metallurgy has to be used to produce them.

Characteristics

Like other groups, the members of this family show patterns in its electron configuration
Electron configuration
In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure...

, especially the outermost shells resulting in trends in chemical behavior (although roentgenium
Roentgenium
Roentgenium is a synthetic radioactive chemical element with the symbol Rg and atomic number 111. It is placed as the heaviest member of the group 11 elements, although a sufficiently stable isotope has not yet been produced in a sufficient amount that would confirm this position as a heavier...

 is probably an exception):
Z
Atomic number
In chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element...

 
Element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...

 
No. of electrons/shell
Electron shell
An electron shell may be thought of as an orbit followed by electrons around an atom's nucleus. The closest shell to the nucleus is called the "1 shell" , followed by the "2 shell" , then the "3 shell" , and so on further and further from the nucleus. The shell letters K,L,M,.....

29 copper 2, 8, 18, 1
47 silver 2, 8, 18, 18, 1
79 gold 2, 8, 18, 32, 18, 1
111 roentgenium 2, 8, 18, 32, 32, 17, 2


They are all relatively inert, corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...

-resistant metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...

s. Copper and gold are colored.

These elements have low electrical resistivity so they are used for wiring. Copper is the cheapest and most widely used. Bond wires for integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

s are usually gold. Silver and silver plated copper wiring are found in some special applications.

Applications

These metals, especially silver, have unusual properties that make them essential for industrial applications outside of their monetary or decorative value. They are all excellent conductors of electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

. The most conductive of all metals are silver, copper and gold in that order. Silver is also the most thermally conductive element, and the most light reflecting element. Silver also has the unusual property that the tarnish that forms on silver is still highly electrically conductive.

Copper is used extensively in electrical wiring and circuitry. Gold contacts are sometimes found in precision equipment for their ability to remain corrosion-free. Silver is used widely in mission-critical applications as electrical contacts, and is also used in photography
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

 (because silver nitrate
Silver nitrate
Silver nitrate is an inorganic compound with chemical formula . This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides...

 reverts to metal on exposure to light), agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

, medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

, audiophile
Audiophile
An audiophile is a person who enjoys listening to recorded music, usually in a home. Some audiophiles are more interested in collecting and listening to music, while others are more interested in collecting and listening to audio components, whose "sound quality" they consider as important as the...

 and scientific applications.

Gold, silver, and copper are quite soft metals and so are easily damaged in daily use as coins. Precious metal may also be easily abraded and worn away through use. In their numismatic
Numismatics
Numismatics is the study or collection of currency, including coins, tokens, paper money, and related objects. While numismatists are often characterized as students or collectors of coins, the discipline also includes the broader study of money and other payment media used to resolve debts and the...

 functions these metals must be alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

ed with other metals to afford coins greater durability. The alloying with other metals makes the resulting coins harder, less likely to become deformed and more resistant to wear.

Gold coins: Gold coin
Gold coin
A gold coin is a coin made mostly or entirely of gold. Gold has been used for coins practically since the invention of coinage, originally because of gold's intrinsic value...

s are typically produced as either 90% gold (e.g. with pre-1933 US coins), or 22 carat
Carat (purity)
The karat or carat is a unit of purity for gold alloys.- Measure :Karat purity is measured as 24 times the purity by mass:where...

 (92%) gold (e.g. current collectible coins and Krugerrand
Krugerrand
The Krugerrand is a South African gold coin, first minted in 1967 to help market South African gold. The coin, produced by the South African Mint, proved popular and by 1980 the Krugerrand accounted for 90% of the gold coin market. The name itself is a compound of Kruger and rand, the South...

s), with copper and silver making up the remaining weight in each case. Bullion gold coins are being produced with up to 99.999% gold (in the Canadian Gold Maple Leaf
Canadian Gold Maple Leaf
The Canadian Gold Maple Leaf is the official bullion gold coin of Canada, and is produced by the Royal Canadian Mint. The brainchild of Walter Ott, it is one of the purest gold regular-issue coins in the world with a gold content of .9999 millesimal fineness , with some special issues .99999 fine...

 series).

Silver coins: Silver coin
Silver coin
Silver coins are possibly the oldest mass produced form of coinage. Silver has been used as a coinage metal since the times of the Greeks. Their silver drachmas were popular trade coins....

s are typically produced as either 90% silver - in the case of pre 1965 US minted coins (which were circulated in many countries), or sterling silver
Sterling silver
Sterling silver is an alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925....

 (92.5%) coins for pre-1920 British Commonwealth and other silver coinage, with copper making up the remaining weight in each case.

Copper coins: Copper coins are often of quite high purity, around 97%, and are usually alloyed with small amounts of zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 and tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

.

Inflation
Inflation
In economics, inflation is a rise in the general level of prices of goods and services in an economy over a period of time.When the general price level rises, each unit of currency buys fewer goods and services. Consequently, inflation also reflects an erosion in the purchasing power of money – a...

 has caused the face value
Face value
The Face value is the value of a coin, stamp or paper money, as printed on the coin, stamp or bill itself by the minting authority. While the face value usually refers to the true value of the coin, stamp or bill in question it can sometimes be largely symbolic, as is often the case with bullion...

 of coins to fall below the hard currency
Hard currency
Hard currency , in economics, refers to a globally traded currency that is expected to serve as a reliable and stable store of value...

 value of the historically used metals. This had led to most modern coins being made of base metals - copper nickel
Cupronickel
Cupronickel or copper-nickel or "cupernickel" is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. Cupronickel is highly resistant to corrosion in seawater, because its electrode potential is adjusted to be neutral with regard to seawater...

 (around 80:20, silver in color) is popular as are nickel-brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...

 (copper (75), nickel (5) and zinc (20), gold in color), manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

-brass (copper, zinc, manganese, and nickel), bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

, or simple plated steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

.

See also

>Explanation of right side periodic table slice: Transition metal
Transition metal
The term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...

s
atomic numbers in black are solids solid borders are older than the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 (Primordial elements)
dashed borders have no isotopes older than the earth
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