Atomic number 47

Silver

Ag
+ phase
− phase

Shells Orbitals 4d 5s

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47 electrons in 5 shells: 2, 8, 18, 18, 1.

Shells are a teaching model: an electron does not travel on a ring at a fixed distance.

Category: Transition metal
Period: 5
Group: 11
Block: d
Standard atomic weight: 107.87(1) Da
Electron configuration: [Kr] 4d¹⁰ 5s¹
Phase at 25 °C: solid
Melting point: 961.78 °C
Boiling point: 2162 °C
Density: 10.501 g/cm³
Electronegativity (Pauling): 1.93
Discovered: Prehistoric times

Neighbours in the table

Pd Cd

In silver, 47 electrons occupy five shells of 2, 8, 18, 18 and 1, written [Kr] 4d¹⁰ 5s¹. Each shell splits into subshells of slightly different energy. In copper, one period up, a full subshell apparently represents a preferred stability, OpenStax says, enough to pull one electron from 4s into 3d. Silver repeats copper’s pattern one shell further out, ten 4d electrons and a single 5s.

Transition elements lose s electrons before d electrons, OpenStax notes, so that lone 5s electron leaves first. What remains is Ag⁺ over a complete 4d core. PubChem gives +1 as its oxidation state, the charge the atom would hold if all its bonds were fully ionic. In the solid the atoms sit in a sea of electrons belonging to no atom in particular. That bonding, OpenStax says, gives a metal its conductivity, lustre and malleability.

Los Alamos ranks pure silver above every other metal for electrical and thermal conductivity; only gold and perhaps palladium are more malleable and ductile. Freshly deposited, no known reflector of visible light beats it, though it reflects ultraviolet poorly. It keeps its lustre in pure air and water, and oxygen leaves it alone even on heating; what dulls old cutlery is ozone, hydrogen sulfide or sulfur in the air.

Where it is found

A kilogram of crust holds 7.5 × 10⁻² milligrams of silver and a litre of seawater 4 × 10⁻⁵, by PubChem’s element record. OpenStax’s own figures rank thulium, rarest of the lanthanoids (elements 57 to 71), above silver in the crust: 4.5 × 10⁻⁵ per cent by mass against 0.79 × 10⁻⁵. Silver reacts with so little that it turns up as nuggets, and its own ores are argentite, Ag₂S, and horn silver, AgCl.

Most comes up as a by-product: the US Geological Survey reports 2024’s silver mainly from lead-zinc, copper and gold mines. World mines gave about 25,000 tonnes, Mexico 6,300, China 3,300, Peru 3,100 and the United States 1,100. Scrap returned another 1,200 tonnes, about 19% of American use.

Freeing it from ore is hydrometallurgy, which turns the metal into soluble ions and reduces them, gives them electrons, back to the element. In air, a cyanide solution dissolves silver metal, Ag₂S and AgCl as the dicyanoargentate(I) ion, [Ag(CN)₂]⁻. Oxygen takes the metal’s electrons, so each atom goes from 0 to 1+; zinc or iron(II) ions later hand electrons back and the metal drops out.

Why it matters

The US Geological Survey’s breakdown of American use in 2024 begins with investment bars, 30%. Electrical and electronic uses take 29%, coins and medals 12%, photovoltaic cells 12%, jewellery and silverware 6%. Conductivity puts it into solder, electrical contacts and printed circuit boards, the Jefferson Lab text in PubChem’s record says.

The survey’s longer list runs from antimicrobial bandages to dental amalgam, where silver and mercury are biocides, killers of living organisms, and so hold back returning decay. World consumption, 37,000 tonnes, outran supply, a reason cited for the average price rising to $27.70 a troy ounce.

A copper wire left in colourless silver nitrate reacts in plain sight. The liquid turns blue while the wire grows a grey, porous coat. OpenStax reads it as electrons passing of their own accord from copper to the silver ions, which come out as fluffy metal. Kept apart and joined by a wire, the same pair makes a galvanic cell whose silver foil is the cathode, where those ions are reduced.

Many countries struck silver coins for centuries, Los Alamos notes; 16th-century Mexican and Peruvian silver went into coins too. Those coins can still be told apart. PubChem’s record notes that silver from those mines and from European mining carries a distinct isotopic signature, its own ratio of silver-107 to silver-109.

Properties

Properties of silver Standard atomic weights from IUPAC/CIAAW (abridged, 2024); other values from PubChem's periodic table, kelvin converted to °C.
Property	Value	Unit	Source
Atomic number	47
Standard atomic weight	107.87(1) Da	Da	IUPAC/CIAAW 2024
Melting point	961.78 °C	°C	Los Alamos: 961.78 °C
Boiling point	2162 °C	°C	Los Alamos: 2162 °C
Density	10.501 g/cm³	g/cm³
Electronegativity (Pauling)	1.93
Electron configuration	1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d¹⁰
Phase at 25 °C	solid

Safety

Silver in a ring or a spoon is a stable, water-insoluble solid. Even so, the EU classification PubChem lists for bulk silver carries the signal word Warning: suspected of damaging fertility, and of organ damage on prolonged or repeated exposure. The concern is dust, mists and soluble compounds at work, where heavy or long exposure can stain the eyes, nose, throat and skin grey-blue, a condition called argyria. PubChem’s safety summary and the NIOSH card for metal dust and soluble compounds are the sheets to read.

Questions

Why does silver tarnish?

Pure air and water do not do it, Los Alamos says, and OpenStax lists it among the four transition metals that oxygen leaves alone even when heated. The tarnish needs ozone, hydrogen sulfide or sulfur in the air, and OpenStax files it under corrosion, an electrochemical process that wears a metal away.

What is sterling silver?

An alloy that is 92.5% silver, with copper or another metal making up the rest, in Los Alamos's description. It is the grade for jewellery and silverware, where appearance comes first, and it is distinct from commercial fine silver, which is at least 99.9% silver. In the US Geological Survey's figures for 2024, jewellery and silverware together took only 6% of American silver use, behind investment bars, electronics, coins and solar cells.

Why is the symbol for silver Ag?

The symbol comes from argentum, the Latin word for silver. PubChem's element record traces it, with the Sanskrit argunas, to a word for bright. The English name has another root altogether, the Anglo-Saxon seofor and siolfur, whose origin is unknown.

Is silver still used in photography?

Far less than it was. OpenStax notes that light-sensitive silver bromide was at one time a component of photographic film, and Los Alamos put about 30% of American industrial consumption into photography. The US Geological Survey's figures for 2024 fold photography into a 7% share with other industrial uses, and name digital imaging, film with less silver and silverless black-and-white film as the substitutes.

When was silver discovered?

No one discovered it. PubChem's element record calls silver known in prehistoric times, and the Jefferson Lab text it carries says people have used it for at least 5,000 years. Los Alamos points to slag heaps in Asia Minor and on Aegean islands as evidence that silver was being separated from lead by 3000 BC. OpenStax counts it with iron, copper and gold as the metals the ancient civilisations knew.

Compounds containing silver

AgNO₃ Silver nitrate 5 atoms in one formula unit of an ionic lattice.

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