Silver
[Kr] 4d¹⁰ 5s¹ · 2 · 8 · 18 · 18 · 1
The best conductor of electricity and heat among all the elements, and the best reflector of visible light. Silver was money for millennia; today more than half of production goes to industry, above all to solar panels.
3D model
Bohr model: nucleus and electron shells from the real configuration. Valence electrons are highlighted.
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Atomic properties
- Atomic number
- 47
- Atomic mass
- 107.868 а.е.м.
- Electron configuration
- [Kr] 4d¹⁰ 5s¹
- Electrons per shell
- 2 · 8 · 18 · 18 · 1
- Block
- d-block
- Group
- Copper group
- Period
- 5
- Electronegativity (Pauling)
- 1.93
- Electronegativity (Allen)
- 1.87
- Atomic radius
- 165 pm
- Covalent radius
- 145 pm
- Van der Waals radius
- 172 pm
- Ionisation energy 1
- 731 kJ/mol
- Ionisation energy 2
- 2 070 kJ/mol
- Ionisation energy 3
- 3 361 kJ/mol
- Electron affinity
- 125.6 kJ/mol
- Common oxidation states
- +1
- Oxidation states
- -2, -1, +1, +2, +3
Physical properties
- State at 25 °C
- solid
- Density
- 10.49 g/cm³
- Melting point
- 1 234.93 K · 961.8 °C
- Boiling point
- 2 435 K · 2 161.9 °C
- Speed of sound
- 2 600 m/s
Thermal properties
- Heat of fusion
- 11.28 kJ/mol
- Heat of vaporisation
- 254 kJ/mol
- Specific heat capacity
- 0.235 J/(g·K)
- Thermal conductivity
- 429 W/(m·K)
Mechanical properties
- Young's modulus
- 83 GPa
- Shear modulus
- 30 GPa
- Bulk modulus
- 100 GPa
- Poisson ratio
- 0.37
- Mohs hardness
- 2.5
- Brinell hardness
- 24.5 MPa
Electrical and magnetic properties
- Electrical resistivity
- 15.87 nΩ·m
- Magnetic ordering
- diamagnetic
- Curie point
- no data
- Néel point
- no data
- Superconducting point
- no data
Crystal structure
- Crystal structure
- face-centred cubic (fcc)
- Lattice constants
- a = 408.53 pm
Abundance
- In the crust
- 0.075 mg/kg
- In the ocean
- 4·10⁻⁵ mg/L
- In the universe
- 0.6 mg/kg
- In the human body
- no data
Isotopes
| Isotope | Abundance | Half-life | Decay mode |
|---|---|---|---|
| 107Ag | 51.839 % | stable | — |
| 109Ag | 48.161 % | stable | — |
Two stable isotopes in near-equal proportion. Silver-108m, half-life 438 years, forms in reactor structures.
Discovery
- Year of discovery
- known since antiquity
- Discovered by
- known since antiquity
- Where
- no data
- Origin of the name
- from Latin argentum (shining); the same root named Argentina
History
Silver was cupelled from lead ores as early as the fourth millennium BCE. Latin argentum means shining; the same root named Argentina, the land of silver.
Where it occurs
0.075 mg/kg of the crust. It occurs native, but is mostly won alongside lead, zinc and copper. Mexico is the largest producer.
How it is produced
From lead-zinc concentrates by the Parkes process and electrolytic refining. About a quarter of supply is recycled silver.
Role in living things
No biological role. Silver ions are toxic to bacteria, disrupting their enzymes and membranes — a fact exploited long before antibiotics.
Safety
Silver salts taken over long periods cause argyria, an irreversible blue-grey discolouration of the skin. Metallic silver itself is harmless.
Uses
- Conductive pastes in photovoltaic modules — the largest industrial use
- Electrical contacts and solders
- Antibacterial coatings and preparations
- Mirrors and optical coatings
- Jewellery, tableware and bullion coins
Curiosities
- Silver conducts better than copper but costs about a hundred times more, which is why wiring is copper.
- The ancients dropped a silver coin into milk to keep it from souring.
- Argentina is the only country named after a chemical element.
- Photography ran on the light sensitivity of silver halides for nearly two centuries.