Element identity
Atomic number, symbol, relative atomic mass display and periodic position are established reference data.
Atomic / electronic model
Ground-state electron configuration and atomic reference values are compiled/evaluated data; orbital graphics are teaching probability models, not photographs.
Material / molecular structure
The displayed ordinary structure is based on established material or molecular science; simplified viewers are labelled as teaching schematics where exact crystallographic coordinates are not rendered.
Temperature / phase path
Transition values are reference/evaluated values for the stated teaching path; pressure, purity and allotropy can matter.
Geography
Real pins use reviewed place/dataset context. Conceptual layers are used when country pins would imply false occurrence, unsafe inventory or an incomplete global distribution.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Gold (Au)
Explore gold as a heavy transition metal, a one-isotope element, an FCC crystal, an unusually yellow metal and a material whose chemistry connects jewellery, electronics, aerospace, mining and nanotechnology.
Gold atomic number, mass, protons, electrons and outer electron
Gold: quick answers
How many protons, neutrons and electrons does gold have?
Gold’s atomic number is 79, so every gold atom has 79 protons, and a neutral atom also has 79 electrons. Its most common natural isotope, gold-197, has 118 neutrons (other isotopes have different neutron counts).
What is the symbol for gold?
The chemical symbol for gold is Au.
Is gold a solid, liquid or gas at room temperature?
Gold is a solid at room temperature (about 25 °C).
What family (group) is gold in?
Gold is a transition metal, in group 11, period 6 of the periodic table.
What is the electron configuration of gold?
The ground-state electron configuration of gold is [Xe] 4f¹⁴ 5d¹⁰ 6s¹.
From atomic number to chemistry
Read these as a chain of causes, not as isolated facts. Each step links to the concept hub if you want the underlying idea explained.
Seventy-nine protons define gold and create the strong nuclear field relevant to its heavy-atom physics.
The filled 5d shell and outer 6s electron are central to gold’s metallic behavior.
Gold sits below copper and silver but heavy-atom relativistic effects modify simple trend expectations.
Gold conducts well and resists ordinary corrosion, helping explain both native occurrence and technical uses.
Gold group, period and position in the periodic table
Gold is a Group 11 transition metal in Period 6. It sits below copper and silver and between platinum and mercury. Group 11 is often called the coinage-metal group because copper, silver and gold have long histories in money and decorative metalwork.
Gold Visual Lab
Decode the Au tile, rotate a true 3D ¹⁹⁷Au nucleus, inspect representative 6s and 5d orbital-shape models, explore the FCC crystal lattice and connect gold chemistry to the real world.
Seven facts packed into one square
Gold in one minute
Au means aurum. The symbol comes from the Latin name for gold.
Gold is naturally yellow. Relativistic effects in this heavy atom help shift visible-light absorption.
It barely tarnishes. Gold is unusually unreactive toward air and many common reagents.
¹⁹⁷Au dominates nature. Natural gold has one stable isotope at essentially 100% abundance.
Soft but useful. Gold’s conductivity and corrosion resistance make it valuable far beyond jewellery.
2 · 8 · 18 · 32 · 18 · 1 electrons
Neutral gold has 79 electrons. The outermost principal shell contains one 6s electron, while the filled 5d subshell is also central to gold’s transition-metal chemistry.
That would imply a classical orbit model. This shell-count diagram is deliberately a counting aid; the Orbitals tab gives a separate probability-cloud model with its own scientific qualification.
Gold adopts a face-centred cubic (FCC), also called cubic close-packed, structure under ordinary conditions. Atoms occupy the cube corners and the centres of each face; those positions are shared with neighboring unit cells in the extended crystal.
[Xe] 4f¹⁴ 5d¹⁰ 6s¹
It is a qualitative learning model for the spatial form and radial structure associated with a 6s-like orbital. The point cloud is not a map of little electron particles moving along paths.
Gold’s one electron in the outermost principal shell is useful for shell counting, but transition-metal chemistry cannot be reduced to “one valence electron.” The filled 5d states lie close enough in energy to matter for bonding, oxidation states and the optical behavior of metallic gold.
Why do people choose gold when cheaper metals exist?
Each use follows from a combination of chemistry and materials properties: corrosion resistance, workability, conductivity, reflectivity and nanoscale optical behavior.
Soft pure gold becomes practical through alloying
Pure gold is highly malleable and relatively soft, so jewellery commonly uses gold alloys to increase hardness and durability. Karat notation expresses how much of the alloy is gold.
Why is gold yellow instead of silver-colored?
The short answer is that gold is heavy enough for relativistic effects to shift its electronic energy structure. That shift moves important absorption into the visible blue region, so the light reflected from bulk gold is richer in yellow and red. The deeper explanation is a chain of four ideas.
Gold has a very heavy nucleus
With atomic number 79, gold has a strong nuclear electric field. Inner and penetrating electrons in heavy atoms require a relativistic quantum description for accurate energies and radial distributions.
The 6s and 5d states shift
Relativity strongly stabilizes and contracts s-like states, especially the 6s state. Indirect relativistic effects also alter the 5d states. The important result is a smaller energy separation than a non-relativistic picture predicts.
Blue light can now be absorbed
In metallic gold, the changed band structure allows strong electronic absorption to reach into the visible blue/violet part of the spectrum instead of remaining mainly at higher ultraviolet energies.
The reflected light looks yellow
White light contains many visible wavelengths. If the surface removes more blue light, the light that comes back to your eyes is relatively enriched in longer yellow/red wavelengths — the characteristic gold color.
Think “white light minus extra blue”
Silver-like metal: visible wavelengths are reflected more evenly, so the surface looks silvery-white.
Gold: stronger blue absorption changes the balance of reflected visible light, producing the yellow appearance.
Teaching diagram only — not a measured reflectance spectrum.
The simple “5d → 6s” story is useful, but solid gold is a band-structure problem
It is common to explain gold’s color using a reduced separation between 5d- and 6s-derived electronic states. That captures the central learning idea, but a piece of gold is a solid: its electrons occupy bands rather than isolated atomic orbitals. A rigorous calculation therefore treats the relativistic electronic band structure of the metal.
The important comparison is with silver. Without relativistic effects, gold’s relevant electronic energies would be much more silver-like and the strongest corresponding absorption would sit at higher energy, outside much of the visible range. Relativity brings the absorption edge into visible blue light, which is why bulk gold does not look silver.
This is not a claim that a gold bar is moving near the speed of light. It means the quantum equations used for electrons in the strong field of a heavy nucleus must include special-relativistic effects to predict the electronic structure accurately.
Gold karat purity explorer: 24K, 22K, 18K, 14K and 9K
Karat measures gold fraction on a 24-part scale. The simple fraction is karat ÷ 24. Real commercial alloys also depend on local hallmarking rules and which alloying metals are used.
24K · essentially pure gold
24 parts out of 24 are gold in the ideal karat fraction. Pure gold is very soft, so lower-karat alloys are often chosen when greater hardness or a different color is desired.
Gold physical, atomic, thermal and chemical properties
The reference data are grouped so the page stays readable. Where compilations differ, the source choice is stated instead of hiding the disagreement.
| Atomic number | 79 | Number of protons; defines the element as gold. |
|---|---|---|
| Relative atomic mass | 196.96657 | Site display rounded from the current NIST/IUPAC reference value. |
| Electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s¹ | Ground-state shorthand. |
| Electronegativity | 2.54 | Pauling scale value used by PubChem; some compilations display a different rounded/reference value. |
| Empirical atomic radius | 135 pm | Empirical radius; do not confuse with van der Waals or covalent radius. |
| 1st ionization energy | 9.225554 eV | NIST reference; approximately 890.1 kJ/mol. |
| Electron affinity | 2.309 eV | PubChem reference value. |
| Appearance | Metallic yellow | Characteristic bulk-metal appearance. |
|---|---|---|
| State near room temperature | Solid | At ordinary reference conditions. |
| Density | ≈19.3 g/cm³ | RSC reference value; PubChem also compiles 19.282 g/cm³. |
| Crystal structure | Face-centred cubic | FCC / cubic close-packed; space group Fm-3m (#225). |
| Lattice parameter a | ≈407.82 pm | Reference crystallographic value used by the 3D teaching model. |
| Group / period / block | 11 / 6 / d | Transition metal; Group 11 with copper and silver. |
| Melting point | 1337.33 K | 1064.18 °C; RSC reference. |
|---|---|---|
| Boiling point | 3109 K | 2836 °C; Element Lookup deliberately uses the RSC reference consistently. |
| Specific heat capacity | 129 J kg⁻¹ K⁻¹ | RSC advanced pressure/temperature data. |
| Temperature tool | Open the interactive state explorer ↓ | |
| Measurement note | Phase boundaries and thermal properties depend on pressure and measurement conditions; this page is a reference view, not a complete pressure-dependent phase diagram. | |
| Electrical behaviour | Good conductor | Metallic electronic structure provides mobile charge carriers. |
|---|---|---|
| Engineering advantage | Conductivity + corrosion resistance | Gold contact surfaces remain chemically stable where surface films would be undesirable. |
| Bulk-conductor context | Copper is usually preferred | Copper is much cheaper and highly conductive; gold is often used as a thin contact coating rather than a bulk wire. |
| Measurement note | Numerical resistivity/conductivity values should be quoted with temperature, purity and material condition; this release keeps the summary qualitative until those fields are provenance-locked. | |
| Common oxidation states | +1, +3 | Most important simple teaching states; additional oxidation states are known in specialized compounds. |
|---|---|---|
| Chemical character | Noble metal | Strong resistance to reaction with air, water and many ordinary reagents. |
| Aqua regia | Gold can dissolve | Gold is corrosion-resistant, not chemically invulnerable. |
| Representative compounds | AuCl · AuCl₃ · HAuCl₄ | Examples spanning gold(I), gold(III) and an important chloroauric-acid precursor used in gold chemistry. |
| Symbol origin | Au | From Latin aurum. |
| Natural stable isotope | ¹⁹⁷Au | Natural isotopic composition is essentially 100% ¹⁹⁷Au. |
|---|---|---|
| ¹⁹⁷Au nucleus | 79 p · 118 n | Mass number 197 minus atomic number 79 gives 118 neutrons. |
| Nuclear spin | 3/2 | NIST isotopic reference. |
| Radioisotope example | ¹⁹⁸Au | RSC lists a half-life of about 2.695 days; radioactive gold is distinct from natural stable ¹⁹⁷Au. |
Gold makes more sense beside copper and silver
Copper, silver and gold share a column of the periodic table, but going down Group 11 changes size, density, energetics and the strength of relativistic effects. Gold’s color is the most visually striking example of that last change.
| Group | 11 |
|---|---|
| Block | d |
| Appearance | reddish metal |
| Group | 11 |
|---|---|
| Block | d |
| Appearance | silvery metal |
| Group | 11 |
|---|---|
| Block | d |
| Appearance | yellow metal |
Why Group 11 elements are compared
All three are transition metals with filled d subshells in their common neutral ground-state descriptions and an outer s electron. They are conductive, workable metals and have long histories in coinage and decorative use.
Heavy-atom effects become chemically important
Gold’s high atomic number makes relativistic effects much stronger than in copper or silver. Those effects help explain not only its yellow color but also aspects of its unusual electron affinity and chemical behavior.
Gold state at temperature: solid, liquid or gas
Use the slider or the three quick-state buttons. This simplified model uses the page’s reference melting and boiling points at approximately standard pressure.
Approximately standard-pressure teaching model. A complete phase diagram also depends on pressure, and reference boiling-point compilations are not perfectly identical.
Where on Earth is gold mined and where are major reserves?
Gold occurs naturally in veins and alluvial/placer deposits, but country dots are most meaningful for modern mine production and reported reserves. The map keeps those concepts separate.
How gold is produced: the high-level process
Gold extraction depends on ore type, deposit geology and the processing route. This is an educational process map, not an operating recipe; industrial mining and chemical recovery require specialist engineering, environmental controls and regulated safety systems.
Find and characterize the deposit
Geologists identify ore bodies or placer deposits and determine how the gold occurs — free grains, veins, or associated with other minerals.
Mine and concentrate
Rock may be crushed and ground, while placer material can be physically concentrated. The aim is to separate a gold-rich stream from much larger amounts of waste material.
Recover the gold
Industrial routes can use gravity separation, flotation and/or controlled hydrometallurgical leaching depending on the ore. The chemistry is chosen for the deposit and operated under engineered containment.
Refine to the required purity
Recovered metal is further purified, cast or converted into feedstock for bullion, jewellery, electronics and other applications.
Gold was known before written chemistry
No single discoverer
Native gold can occur as metal, so people used and valued it long before modern chemistry existed.
Jewellery, ornament and status
Gold’s rarity, workability and resistance to tarnish made it a prestige material across many early civilizations.
From Latin aurum
The chemical symbol Au comes from the Latin name for gold rather than the English word.
From coinage to electronics
Gold remains important in jewellery and finance while also serving high-reliability electrical, optical and technological roles.
What is gold used for?
Jewellery + decorative arts
Gold’s color, workability and resistance to tarnish make it ideal for jewellery, gilding and decorative surfaces.
Electrical contacts
Gold conducts electricity and resists corrosion, helping maintain reliable contacts in electronic devices.
Infrared-reflective coatings
Thin gold coatings are used where stable infrared reflection and chemical inertness are useful, including some aerospace and optical applications.
Bullion + monetary history
Gold has been used for coinage and monetary reserves because it is durable, scarce, recognizable and easily divided or remelted.
Dentistry + specialized alloys
Gold alloys have a long history in dental restorations because they combine workability with strong corrosion resistance.
Nanoparticles + catalysis
At nanoscale dimensions, gold can show useful optical and catalytic behaviors very different from bulk metal.
Representative gold compounds and oxidation states
Elemental gold is famous for low reactivity, but gold still forms an important range of compounds. The most useful school-level distinction is between gold(I) and gold(III) chemistry.
Gold(I)
Gold(I), often called aurous gold, is a common oxidation state in coordination chemistry. AuCl is a simple representative formula, although real structures and solution species can be more complex than a one-line formula suggests.
Gold(III)
Gold(III), often called auric gold, is another central oxidation state. AuCl₃ is a familiar representative formula used when introducing gold(III) chemistry.
Chloroaurate chemistry
Tetrachloroauric-acid/chloroaurate chemistry is widely used as a soluble gold precursor in laboratory and materials contexts, including routes to gold nanoparticles.
Natural gold has one stable isotope: ¹⁹⁷Au
Radioactive gold isotopes exist too
Gold-198 is a short-lived radioisotope; RSC lists a half-life of about 2.695 days. It has specialized research and medical history. It is not part of natural stable gold and should not be confused with ordinary ¹⁹⁷Au.
Five-question Gold check
What is gold’s atomic number?
Which isotope makes up natural gold?
What crystal structure does gold have?
What does 18K gold mean ideally?
Why is gold useful for electrical contacts?
Gold questions: quick answers first, then the full explanation
Each question starts with the fact a student may need immediately, followed by the deeper chemistry or materials explanation.
What is gold’s atomic number, and how many protons, neutrons and electrons does it have?
Short answer: Gold’s atomic number is 79, so every gold atom has 79 protons. Neutral gold has 79 electrons. Natural ¹⁹⁷Au has 118 neutrons.
Atomic number is defined by proton count, so 79 protons identify the element as gold. A neutral atom carries the same number of electrons as protons, giving 79 electrons.
Natural gold is essentially all ¹⁹⁷Au. Subtracting atomic number 79 from mass number 197 gives 118 neutrons in that isotope.
What is gold’s electron configuration?
Short answer: [Xe] 4f¹⁴ 5d¹⁰ 6s¹.
The xenon core accounts for 54 electrons. The remaining electrons fill 4f¹⁴, 5d¹⁰ and 6s¹, bringing the total to 79.
The single 6s electron is the outermost-shell electron, but gold is a transition metal: its filled 5d subshell also matters when explaining bonding, oxidation states and relativistic effects.
How many electron shells does gold have?
Short answer: A neutral gold atom has electrons in six principal shells, from n = 1 through n = 6.
The shell-count model groups gold’s 79 electrons as 2, 8, 18, 32, 18 and 1. Its outermost principal shell has one 6s electron, but the 5d electrons also matter for gold’s bonding and other transition-metal properties.
These numbers help count electrons; actual electrons occupy quantum states rather than fixed circular paths around the nucleus. The ground-state configuration above gives the more detailed orbital description.
How many valence electrons does gold have?
Short answer: Gold has one electron in its outermost principal shell (6s¹), but “valence electrons” in transition metals is more nuanced than simple main-group counting.
If a school question asks for the outermost-shell electron count, the answer is one. However, gold chemistry cannot be understood by pretending only that one electron matters.
The 5d electrons lie close enough in energy to participate in bonding and oxidation-state chemistry. That is why transition metals are often discussed using both ns and (n−1)d electrons rather than a single main-group-style valence count.
Why is the symbol for gold Au?
Short answer: Au comes from the Latin word aurum.
Chemical symbols are international identifiers, and some preserve older Latin names rather than modern English names. Gold is Au from aurum, just as iron is Fe from ferrum and silver is Ag from argentum.
Gold itself was known in prehistoric times, so there is no single modern discoverer associated with the element.
Why is gold yellow?
Short answer: Relativistic effects in heavy gold atoms alter electronic energy levels so blue light is absorbed more strongly, leaving reflected light enriched toward yellow and red.
Most metals reflect visible wavelengths fairly evenly and therefore look silvery. Gold is heavy enough that relativistic effects significantly change the energies and radial behavior of its electrons.
In simplified terms, these effects narrow the energy separation relevant to transitions between gold’s 5d-derived states and the 6s/Fermi-level region. The absorption shifts into the visible blue part of the spectrum. Remove more blue from white light and the reflected light looks yellow-gold.
Why is gold so unreactive, and why does it not tarnish easily?
Short answer: Metallic gold is a noble metal whose electronic energetics make oxidation by ordinary air and water unfavorable, so it does not readily form the oxide/sulfide surface films seen on many other metals.
Gold’s nobility is connected to its high reduction potential and to heavy-element electronic structure, including relativistic effects that influence its 6s and 5d orbitals. The result is unusually weak driving force for many everyday corrosion reactions.
“Unreactive” is not “chemically impossible to react.” Gold can form compounds and can be dissolved under sufficiently oxidizing and complexing chemical conditions. Its value in contacts and coatings comes from resistance to ordinary surface corrosion, not absolute inertness.
Key point: Gold resists common oxidation conditions, but suitable chemical environments can still convert Au(0) into compounds.
What is 24K, 18K or 14K gold?
Short answer: Karat expresses gold fraction on a 24-part scale: 24K is ideally 24/24 gold, 18K is 18/24 = 75%, and 14K is about 58.3%.
Pure gold is soft, so jewellery often mixes gold with metals such as copper, silver, palladium or others to change hardness, color and working properties.
The mathematical karat fraction is simple, but legal hallmarking standards and permitted tolerances vary by country. The on-page calculator is therefore an educational purity conversion, not a hallmark certification tool.
Where is gold found naturally?
Short answer: Gold occurs as native metal and in ores, commonly associated with veins and alluvial/placer deposits.
Because gold is relatively unreactive, it is one of the few metals that can occur naturally in elemental form. Weathering can free dense gold particles from rock, allowing them to concentrate in river and placer sediments.
Modern mining also recovers gold from hard-rock deposits and as a by-product of processing some base-metal ores. That is why the geography section distinguishes natural occurrence from current mine-production statistics.
Which countries mine the most gold?
Short answer: USGS estimates that China, Russia, Australia, Canada and the United States were the five leading gold producers in 2025.
Mine-production rankings can change from year to year, so Element Lookup labels the map with the source year rather than presenting production as a timeless property of the element.
For 2025, USGS estimates roughly 380 t for China, 310 t for Russia, 280 t for Australia, 200 t for Canada and 160 t for the United States.
Why is gold used in electronics if copper conducts electricity well too?
Short answer: Gold combines useful electrical conductivity with exceptional resistance to corrosion at contact surfaces.
Copper is widely used as a bulk conductor because it is highly conductive and far less expensive. But exposed copper surfaces can oxidize, and surface films can increase contact resistance.
A thin gold layer can preserve a clean, stable contact surface in connectors and other high-reliability components. The engineering advantage is not simply conductivity; it is conductivity plus chemical stability.
Scientific sources for Gold
Core atomic data, isotope information, physical properties, crystal structure, uses and modern geographic figures are cross-checked against scientific and government sources. Year-dependent mining statistics are labeled with their source year.
- PubChem — Gold properties, identifiers, uses, isotope and provenance links
- Royal Society of Chemistry — Gold reference data, appearance, history and uses
- NIST — Gold atomic weight, ground-state configuration and ionization energy
- USGS Mineral Commodity Summaries 2026 — mine production and reserves
- WebElements — FCC crystal structure and lattice parameter
- RSC Publishing — relativistic context for gold’s electronic structure and yellow color
Questions to ask next about Gold
A good element lesson should lead to the next useful question, not end after a list of facts.
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