Silver

Silver is a chemical element with the symbol Ag (from the Latin argentum, derived from the Proto-Indo-European h₂erǵ: "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal.[5] The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.

Silver, 47Ag
Silver
Appearancelustrous white metal
Standard atomic weight Ar°(Ag)
  • 107.8682±0.0002
  • 107.87±0.01 (abridged)[1]
Silver in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Cu

Ag

Au
palladiumsilvercadmium
Atomic number (Z)47
Groupgroup 11
Periodperiod 5
Block  d-block
Electron configuration[Kr] 4d10 5s1
Electrons per shell2, 8, 18, 18, 1
Physical properties
Phase at STPsolid
Melting point1234.93 K (961.78 °C, 1763.2 °F)
Boiling point2435 K (2162 °C, 3924 °F)
Density (near r.t.)10.49 g/cm3
when liquid (at m.p.)9.320 g/cm3
Heat of fusion11.28 kJ/mol
Heat of vaporisation254 kJ/mol
Molar heat capacity25.350 J/(mol·K)
Vapour pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1283 1413 1575 1782 2055 2433
Atomic properties
Oxidation states−2, −1, 0,[2] +1, +2, +3 (an amphoteric oxide)
ElectronegativityPauling scale: 1.93
Ionisation energies
  • 1st: 731.0 kJ/mol
  • 2nd: 2070 kJ/mol
  • 3rd: 3361 kJ/mol
Atomic radiusempirical: 144 pm
Covalent radius145±5 pm
Van der Waals radius172 pm
Spectral lines of silver
Other properties
Natural occurrenceprimordial
Crystal structure face-centred cubic (fcc)
Speed of sound thin rod2680 m/s (at r.t.)
Thermal expansion18.9 µm/(m⋅K) (at 25 °C)
Thermal conductivity429 W/(m⋅K)
Thermal diffusivity174 mm2/s (at 300 K)
Electrical resistivity15.87 nΩ⋅m (at 20 °C)
Magnetic orderingdiamagnetic[3]
Molar magnetic susceptibility−19.5×10−6 cm3/mol (296 K)[4]
Young's modulus83 GPa
Shear modulus30 GPa
Bulk modulus100 GPa
Poisson ratio0.37
Mohs hardness2.5
Vickers hardness251 MPa
Brinell hardness206–250 MPa
CAS Number7440-22-4
History
Discoverybefore 5000 BC
Symbol"Ag": from Latin argentum
Main isotopes of silver
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
105Ag syn 41.2 d ε 105Pd
γ
106mAg syn 8.28 d ε 106Pd
γ
107Ag 51.839% stable
108mAg syn 439 y ε 108Pd
IT 108Ag
γ
109Ag 48.161% stable
110mAg syn 249.95 d β 110Cd
γ
111Ag syn 7.45 d β 111Cd
γ
 Category: Silver
| references

Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes alongside gold:[6] while it is more abundant than gold, it is much less abundant as a native metal.[7] Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of the seven metals of antiquity, silver has had an enduring role in most human cultures.

Other than in currency and as an investment medium (coins and bullion), silver is used in solar panels, water filtration, jewellery, ornaments, high-value tableware and utensils (hence the term "silverware"), in electrical contacts and conductors, in specialized mirrors, window coatings, in catalysis of chemical reactions, as a colorant in stained glass, and in specialized confectionery. Its compounds are used in photographic and X-ray film. Dilute solutions of silver nitrate and other silver compounds are used as disinfectants and microbiocides (oligodynamic effect), added to bandages, wound-dressings, catheters, and other medical instruments.


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