Quick Facts
| Property | Value |
|---|---|
| Symbol | Ag |
| Atomic Number | 47 |
| Atomic Mass | 107.87 u |
| Category | Transition Metal |
| Period | 5 |
| Group | 11 |
| Block | d |
| Electron Configuration | [Kr] 4d¹⁰ 5s¹ |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 10.49 g/cm³ |
| Melting Point | 961.78°C (1234.93 K) |
| Boiling Point | 2162°C (2435 K) |
| Appearance | Lustrous, white metallic |
Atomic Properties
| Property | Value |
|---|---|
| Electron Configuration | [Kr] 4d¹⁰ 5s¹ |
| Electronegativity | 1.93 (Pauling scale) |
| First Ionization Energy | 731.0 kJ/mol |
| Atomic Radius | 144 pm |
| Covalent Radius | 145 pm |
| Van der Waals Radius | 172 pm |
History and Discovery
Discovered by: Known since antiquity Year of Discovery: ~3000 BCE Location: Anatolia (modern Turkey)
Etymology
The symbol "Ag" comes from Latin "argentum" (shiny), related to Greek "argyros." The English "silver" comes from Germanic roots.
Discovery Story
Silver has been known since ancient times and was one of the first five metals discovered (with gold, copper, lead, and iron). Ancient civilizations in Anatolia were smelting silver by 3000 BCE. The Romans obtained vast quantities from Spain. Silver played crucial roles in economies worldwide.
Isotopes
| Isotope | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|
| ¹⁰⁷Ag | 51.839% | Stable | - |
| ¹⁰⁹Ag | 48.161% | Stable | - |
Occurrence
Natural Abundance
Silver comprises about 0.075 ppm of Earth's crust. It is found native and in ores like argentite (Ag₂S), horn silver (AgCl), and with lead, copper, and gold ores. Major producers are Mexico, Peru, China, and Russia.
Extraction and Production
- Byproduct: From lead, copper, and zinc refining (70%)
- Primary Mining: From silver-rich ores (30%)
- Parkes Process: Extraction from lead
- Global production: about 25,000 tons annually
Applications and Uses
Investment and Currency
- Silver coins and bars
- Central bank reserves
- Investment vehicles
Industrial Applications
- Electronics (best electrical conductor)
- Solar panels (photovoltaic cells)
- Brazing alloys and solders
- Batteries
Photography (Declining)
- Silver halides for photographic film
- X-ray film
Other Uses
- Jewelry and silverware
- Mirrors and reflective coatings
- Water purification (antimicrobial)
- Medical devices
Biological Role
Silver has no essential biological role but has antimicrobial properties.
In the Human Body
Silver is not normally needed by the body. Argyria (bluish skin discoloration) results from excessive silver exposure.
Antimicrobial Properties
Silver ions and nanoparticles are effective against bacteria, used in wound dressings, catheters, and water treatment.
Safety and Hazards
Toxicity
Metallic silver is considered non-toxic. Chronic exposure to silver compounds can cause argyria. Silver nitrate is caustic.
Handling Precautions
- Silver nitrate stains skin and clothing
- Some silver compounds are irritating
- Argyria from chronic exposure is permanent
- Standard metal handling procedures
Environmental Impact
Silver mining has environmental impacts. Silver in aquatic environments can be toxic to some organisms. Silver from photographic processing was once a major concern.
Interesting Facts
- Silver has the highest electrical and thermal conductivity of all metals
- The word "silver" is in many languages' words for money (French "argent")
- The term "sterling silver" refers to 92.5% silver alloy
- Silver was once more valuable than gold in ancient Egypt
- Colloidal silver supplements are marketed but have no proven benefits