Group of elements in the periodic table
Group 11
, by modern
IUPAC
numbering,
[1]
is a
group
of
chemical elements
in the
periodic table
, consisting of
copper
(Cu),
silver
(Ag),
gold
(Au), and
roentgenium
(Rg), although no chemical experiments have yet been carried out to confirm that roentgenium behaves like the heavier
homologue
to gold. Group 11 is also known as the
coinage metals
, due to their usage in minting coins
[2]
?while the rise in metal prices mean that silver and gold are no longer used for circulating currency, remaining in use for bullion, copper remains a common metal in coins to date, either in the form of copper
clad coinage
or as part of the
cupronickel
alloy.
[
citation needed
]
They were most likely the first three elements discovered.
[3]
Copper, silver, and gold all occur naturally in
elemental form
.
[4]
[5]
History
[
edit
]
All three stable elements of the group have been known since prehistoric times,
[2]
as all of them occur in metallic form in nature and no
extraction metallurgy
is necessary to produce them.
Copper was known and used around 4000 BC and many items, weapons and materials were made and used with copper.
The first evidence of silver mining dates back to 3000 BC, in Turkey and Greece, according to the RSC. Ancient people even figured out how to refine silver.
The earliest recorded metal employed by humans appears to be gold, which can be found
free
or "
native
". Small amounts of natural gold have been found in Spanish caves used during the late
Paleolithic
period, c. 40,000 BC. Gold artifacts made their first appearance at the very beginning of the
pre-dynastic period in Egypt
, at the end of the fifth millennium BC and the start of the fourth, and smelting was developed during the course of the 4th millennium BC; gold artifacts appear in the archeology of
Lower Mesopotamia
during the early 4th millennium BC.
Roentgenium was made in 1994 by bombarding nickel-64 atoms into
bismuth-209
to make roentgenium-272.
[6]
Characteristics
[
edit
]
Like other groups, the members of this family show patterns in
electron configuration
, especially in the outermost shells, resulting in trends in chemical behavior, although roentgenium is probably an exception:
Z
|
Element
|
No. of electrons/shell
|
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 (predicted)
|
All group 11 elements are relatively inert,
corrosion
-resistant
metals
. Copper and gold are colored, but silver is not. Roentgenium is expected to be silvery, though it has not been produced in large enough amounts to confirm this.
These elements have low
electrical resistivity
so they are used for wiring. Copper is the cheapest and most widely used.
Bond wires
for
integrated circuits
are usually gold. Silver and silver-plated copper wiring are found in some special applications.
Occurrence
[
edit
]
Copper occurs in its native form in Chile, China, Mexico, Russia and the USA. Various natural ores of copper are:
copper pyrites
(CuFeS
2
),
cuprite
or ruby copper (Cu
2
O),
copper glance
(Cu
2
S),
malachite
(Cu(OH)
2
CuCO
3
), and
azurite
(Cu(OH)
2
2CuCO
3
).
Copper pyrite is the principal ore, and yields nearly 76% of the world production of copper.
Production
[
edit
]
Silver is found in native form, as an alloy with gold (
electrum
), and in ores containing
sulfur
,
arsenic
,
antimony
or
chlorine
. Ores include
argentite
(Ag
2
S),
chlorargyrite
(AgCl) which includes
horn silver
, and
pyrargyrite
(Ag
3
SbS
3
). Silver is extracted using the
Parkes process
.
Applications
[
edit
]
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
. The most conductive (by volume) 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
(because
silver nitrate
reverts to metal on exposure to light),
agriculture
,
medicine
,
audiophile
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
functions these metals must be
alloyed
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 coins
are typically produced as either 90% gold (e.g. with pre-1933 US coins), or 22
carat
(91.66%) gold (e.g. current
collectible coins
and
Krugerrands
), 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
series).
Silver coins:
Silver coins
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
(92.5%) coins for pre-1920 British Commonwealth and other silver coinage, with copper making up the remaining weight in each case. Old European coins were commonly produced with 83.5% silver. Modern silver bullion coins are often produced with purity varying from 99.9% to 99.999%.
Copper coins:
Copper coins are often of quite high purity, around 97%, and are usually alloyed with small amounts of
zinc
and
tin
.
Inflation
has caused the
face value
of coins to fall below the
hard currency
value of the historically used metals. This had led to most modern coins being made of
base metals
?
copper nickel
(around 80:20, silver in color) is popular as are nickel-
brass
(copper (75), nickel (5) and zinc (20), gold in color),
manganese
-brass (copper, zinc, manganese, and nickel),
bronze
, or simple plated
steel
.
Biological role and toxicity
[
edit
]
Copper, although toxic in excessive amounts, is
essential for life
. It can be found in
hemocyanin
,
cytochrome c oxidase
and in
superoxide dismutase
. Copper is shown to have
antimicrobial
properties which make it useful for hospital doorknobs to keep diseases from being spread. Eating food in copper containers is known to increase the risk of
copper toxicity
.
Wilson's disease
is a genetic condition in which a protein important for excretion of excess copper is mutated such that copper builds up in body tissues, causing symptoms including vomiting, weakness, tremors, anxiety, and muscle stiffness.
Elemental gold and silver have no known toxic effects or biological use, although gold
salts
can be toxic to liver and kidney tissue.
[7]
[8]
Like copper, silver also has
antimicrobial properties
. The prolonged use of preparations containing gold or silver can also lead to the accumulation of these metals in body tissue; the results of which are irreversible but apparently harmless pigmentation conditions known as
chrysiasis
and
argyria
respectively.
Due to being short lived and radioactive,
roentgenium
has no biological use but it is likely extremely harmful due to its radioactivity.
References
[
edit
]
- ^
Fluck, E. (1988).
"New Notations in the Periodic Table"
(PDF)
.
Pure Appl. Chem.
60
(3).
IUPAC
: 431?436.
doi
:
10.1351/pac198860030431
. Retrieved
24 March
2012
.
- ^
a
b
"23.6: Group 11: Copper, Silver, and Gold"
.
Chemistry LibreTexts
. 2015-01-18
. Retrieved
2022-03-25
.
- ^
Greenwood, Norman N.
; Earnshaw, Alan (1997).
Chemistry of the Elements
(2nd ed.).
Butterworth-Heinemann
. p. 1173.
ISBN
978-0-08-037941-8
.
- ^
"These Are the Native Elements That Occur in Nature"
.
ThoughtCo
. Retrieved
2022-03-25
.
- ^
"List Native Elements Minerals & Naturally Occurring Metals In Pure Form"
.
Mineral Processing & Metallurgy
. 2016-09-27
. Retrieved
2022-03-25
.
- ^
Hofmann, S.; Ninov, V.; Heßberger, F.P.; Armbruster, P.; Folger, H.; Munzenberg, G.; Schott, H. J.; Popeko, A. G.; Yeremin, A. V.; Andreyev, A. N.; Saro, S.; Janik, R.; Leino, M. (1995). "The new element 111".
Zeitschrift fur Physik A
.
350
(4): 281?282.
Bibcode
:
1995ZPhyA.350..281H
.
doi
:
10.1007/BF01291182
.
- ^
Wright, I. H.; Vesey, C. J. (1986).
"Acute poisoning with gold cyanide"
.
Anaesthesia
.
41
(79): 936?939.
doi
:
10.1111/j.1365-2044.1986.tb12920.x
.
PMID
3022615
.
- ^
Wu, Ming-Ling; Tsai, Wei-Jen; Ger, Jiin; Deng, Jou-Fang; Tsay, Shyh-Haw; Yang, Mo-Hsiung. (2001). "Cholestatic Hepatitis Caused by Acute Gold Potassium Cyanide Poisoning".
Clinical Toxicology
.
39
(7): 739?743.
doi
:
10.1081/CLT-100108516
.
PMID
11778673
.
|
---|
|
Copper
Cu
Atomic Number: 29
Atomic Weight: 63.546
Melting Point: 1357.75 K
Boiling Point: 2835 K
Specific mass: 8.96 g/cm
3
Electronegativity: 1.9
|
Silver
Ag
Atomic Number: 47
Atomic Weight: 107.8682
Melting Point: 1234.15 K
Boiling Point: 2435 K
Specific mass: 10.501 g/cm
3
Electronegativity: 2.2
|
Gold
Au
Atomic Number: 79
Atomic Weight: 196.966569
Melting Point: 1337.73 K
Boiling Point: 3129 K
Specific mass: 19.282 g/cm
3
Electronegativity: 2.54
|
Roentgenium
Rg
Atomic Number: 111
Atomic Weight: [281]
Melting Point: ? K
Boiling Point: ? K
Specific mass: ? 28.7 g/cm
3
Electronegativity: ?
|
|