Silver Element Facts


Silver

Silver nuggets found in the field - native silver.

47
Ag
107.9

Data Zone

Classification: Silver is a transition metal
Color: silver
Atomic weight: 107.868
State: solid
Melting point: 961.95 oC, 1235.1 K
Boiling point: 2155 oC, 2428 K
Electrons: 47
Protons: 47
Neutrons in most abundant isotope: 60
Electron shells: 2,8,18,18,1
Electron configuration: [Kr] 4d10 5s1
Density @ 20oC: 10.5 g/cm3
Show more, including: Heats, Energies, Oxidation, Reactions, Compounds, Radii, Conductivities
Atomic volume: 10.3 cm3/mol
Structure: fcc: face-centered cubic
Hardness: 2.5 mohs
Specific heat capacity 0.235 J g-1 K-1
Heat of fusion 11.30 kJ mol-1
Heat of atomization 284 kJ mol-1
Heat of vaporization 250.580 kJ mol-1
1st ionization energy 731 kJ mol-1
2nd ionization energy 2073.5 kJ mol-1
3rd ionization energy 3360.6 kJ mol-1
Electron affinity 125.6 kJ mol-1
Minimum oxidation number 0
Min. common oxidation no. 0
Maximum oxidation number 3
Max. common oxidation no. 1
Electronegativity (Pauling Scale) 1.93
Polarizability volume 7.9 Å3
Reaction with air mild, ⇒ Ag2O
Reaction with 15 M HNO3 mild, ⇒ AgNO3
Reaction with 6 M HCl none
Reaction with 6 M NaOH
Oxide(s) Ag2O, AgO (silver peroxide:Ag2O.Ag2O3)
Hydride(s)
Chloride(s) AgCl
Atomic radius 160 pm
Ionic radius (1+ ion) 128 pm
Ionic radius (2+ ion) 108 pm
Ionic radius (3+ ion) 89 pm
Ionic radius (1- ion)
Ionic radius (2- ion)
Ionic radius (3- ion)
Thermal conductivity 429 W m-1 K-1
Electrical conductivity 62.9 x 106 S m-1
Freezing/Melting point: 961.95 oC, 1235.1 K



Galena

Galena (lead sulfide). Galena would have been noticed by anyone looking for metals in ancient times. Galena generally contains silver, sometimes in significant quantities. Image: Rob Lavinsky, iRocks.com

Discovery of Silver

Dr. Doug Stewart

Silver has been in use since prehistoric times. We do not know who its discoverer was, although the discovery would almost certainly have been of native silver.

Nuggets of native silver metal can be found in minerals and sometimes in rivers; but they are rare. Despite native silver’s rarity, very large pieces of it have been found, such as “pieces of native silver as big as stove lids and cannon balls” found in the early 1900s in Northern Ontario, Canada. (1)

Silver has a special place in the history of the elements because it is one of the first five metals discovered and used by humans. The others were gold, copper, lead and iron.

Silver objects dating from before 4000 BC have been found in Greece and from slightly later in Anatolia (in modern Turkey). Silver artifacts have been found in the Sumerian city of Kish dating from about 3000 BC. (2), (3), (4)

Silver and lead often appear together in nature, for example in the mineral galena which is mainly lead sulfide. Galena actually looks metallic (see image) and would have caught the eyes of people looking for metals.

The silver objects found in Greece, Turkey and Kish were made of silver that was refined from lead-containing ores such as galena. (Humans have been successful chemists for a surprisingly long time.)

First the ore was smelted under reducing conditions to obtain a mixture of silver and lead. The metals then went through cupellation: the metals were heated to about 1000 oC in a strong stream of air. Under these conditions lead reacts with oxygen forming lead oxide, leaving liquid silver metal floating on top. (3), (4)

Our name for the element is derived from the Anglo-Saxon for silver, ‘seolfor,’ which itself comes from ancient Germanic ‘silabar.’

Silver’s chemical symbol, Ag, is an abbreviation of the Latin word for silver, ‘argentum.’ The Latin word originates from argunas, a Sanskrit word meaning shining. (5)

The historical association between silver and money is still found in some languages. The French word for silver is argent, and the same word is used for money. The Romans used the word ‘argentarius’ to mean banker (silver trader). (6)

Silver tarnishes quickly in sulfur dioxide released from a boiled egg, then the tarnish is instantly removed using electrochemistry.

A demonstration of basic photography using silver chloride.


Appearance and Characteristics

Harmful effects:

Silver is considered to be non-toxic. However, most silver salts are poisonous and some may be carcinogenic.

Characteristics:

Silver is a soft, ductile, malleable, lustrous metal. It has the highest electrical and thermal conductivity of all metals.

Silver is stable in oxygen and water, but tarnishes when exposed to sulfur compounds in air or water to form a black sulfide layer.

Uses of Silver

Sterling silver (an alloy of 92.5% silver and 7.5% copper) or Britannia silver (an alloy of 95.8% silver and 4.2% copper) are used for jewelry and silverware.

Silver is used as a food additive/coloring and is given the E number E174.

About 30% of silver produced is used in the photographic industry, mostly as silver nitrate.

Silver is used in solders, electrical contacts, and silver-cadmium and silver-zinc batteries. Silver paints are used in the manufacture of electronic printed circuits.

It is used in superior mirror production, as silver is the best known reflector of visible light, although it does tarnish over time.

Silver iodide is used in artificial rain making to seed clouds.

Silver compounds were used successfully to prevent infection in World War 1.

Abundance and Isotopes

Abundance earth’s crust: 75 parts per billion by weight, 20 parts per billion by moles

Abundance solar system: 1 part per billion by weight, 10 parts per trillion by moles

Cost, pure: $120 per 100g

Cost, bulk: $57.5 per 100g

Source: Silver is found in elemental form and also in various ores such as argentite (silver sulfide, Ag2S) and horn silver (silver chloride, AgCl). Commercially, the main sources of silver are copper, copper-nickel, gold, lead, and lead-zinc ores. Silver is extracted from the anode waste sludges of electrolytic copper-refining.

Isotopes: Silver has 35 isotopes whose half-lives are known, with mass numbers 94 to 128. Naturally occurring silver is a mixture of its two stable isotopes, 107Ag and 109Ag with natural abundances of 51.8% and 48.2% respectively.

References

1. Charles Dumaresq, The Rise and Fall of a Mining Camp., Cobalt Mining Legacy.
2. Barbara S. Ottaway and Ben Roberts, The Emergence of Metalworking., Prehistoric Europe: Theory and Practice edited by Andrew Jones, 2008, p208, Wiley-Blackwell.
3. Hadi Ozbal, Ancient Anatolian Metallurgy., 2001. (pdf download)
4. Mesopotamia, The International History Project, 2003.
5. Vivi Ringnes, Origin of the Names of Chemical Elements., J. Chem. Educ., 1989, 66 (9), p731.
6. Thomas Patrick Mohide, The International Silver Trade., 1992, p2, Woodhead Publishing.

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Comments

  1. great resource!

  2. luz ariana says:

    this really helps for my “adopt an element project”

  3. i found this site more helpful than any other for writing my report on silver