47
Ag
107.868
Silver
General | States | Energies
Oxidation & Electrons | Appearance & Characteristics
Reactions | Compounds | Radius | Conductivity
Abundance & Isotopes

Silver
Silver nuggets, found in the field - native silver.




General:

Name: Silver Symbol: Ag
Type: Transition Metal Atomic weight: 107.868
Density @ 293 K: 10.5 g/cm3 Atomic volume: 10.3 cm3/mol
Discovered: Silver has been known since ancient times. Evidence suggests that silver was being separated from lead as early as 3000 B.C. The name silver is derived from the Anglo-Saxon 'seolfor' meaning silver. Its chemical symbol, Ag, is an abbreviation of the Latin word for silver, 'argentum'.

States

State (s, l, g): solid
Melting point: 1235.1 K   (961.95 oC) Boiling point: 2428 K   (2155 oC)

Energies

Specific heat capacity: 0.235 J g-1 K-1 Heat of atomization: 284 kJ mol-1
Heat of fusion: 11.30 kJ mol-1 Heat of vaporization (sublimation): 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

Oxidation & Electrons

Shells: 2,8,18,18,1 Electron configuration: [Kr] 4d10 5s1
Minimum oxidation number: 0 Maximum oxidation number: 3
Min. common oxidation no.: 0 Max. common oxidation no.: 1
Electronegativity (Pauling Scale): 1.93 Polarizability volume: 7.9 Å3

Appearance & Characteristics

Structure: fcc: face-centered cubic Color: silver
Harmful Effects: Silver is considered to be non-toxic. However, most silver salts are poisonous and some may be carcinogenic. Hardness: 2.5 mohs
Characteristics: Silver is a soft, ductile, malleable, lustrous metal. It has the highest electrical and thermal conductivity of all metals, and has the lowest contact resistance. 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: Sterling silver is used for jewelry, silverware, etc. where appearance is important. This alloy contains 92.5% silver, the remainder being copper or another metal. 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 making solder and brazing alloys, dental alloys, electrical contacts, and high capacity silver-zinc and silver-cadmium batteries. Silver paints are used for making printed circuits. It is used in superior mirror production, as silver is the best reflector of visible light known, although it does tarnish over time. Silver iodide is used in seeding clouds to produce rain. Silver compounds were used successfully to prevent infection in World War 1.

Reactions

Reaction with air: mild, ⇒ Ag2O Reaction with 6 M HCl: none
Reaction with 3 M HNO3: mild, ⇒ AgNO3 Reaction with 6 M NaOH:

Compounds

Oxide(s): Ag2O, AgO (silver peroxide:Ag2O.Ag2O3) Chloride(s): AgCl
Hydride(s): none

Radius

Atomic radius: 160 pm Ionic radius (1+ ion): 128 pm
Ionic radius (2+ ion): 108 pm Ionic radius (3+ ion): 89 pm
Ionic radius (2- ion): pm Ionic radius (1- ion): pm

Conductivity

Thermal conductivity: 429 W m-1 K-1 Electrical conductivity: 63.0 x 106 S m-1

Abundance & Isotopes

Abundance earth's crust: 80 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 $/100g
Cost, bulk: 14 $/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 also recovered during electrolytic refining of copper.
Isotopes: Silver has 35 isotopes whose half-lives are known, with mass numbers 94 to 128. Of these, two are stable, 107Ag and 109Ag.