Atomic / phase data
Reference values are evaluated.
A7 structure
Rhombohedral A7 bulk structure is measured.
209Bi radioactivity
Natural 209Bi alpha decay is measured; its half-life is extraordinarily long.
Uses
Metal, alloys and bismuth compounds are kept distinct.
Geography
Commodity context is dated/selective.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Bismuth (Bi)
Bismuth is element 83, a heavy post-transition metal with a rhombohedral structure, unusually low toxicity relative to many neighboring heavy metals, and a natural isotope—²⁰⁹Bi—that is radioactive only on an immense timescale.
Bismuth atomic number, mass, electron configuration and key properties
Bismuth has 83 protons. A neutral bismuth atom has 83 electrons; bismuth-209 has 126 neutrons. An isotope’s neutron count comes from its mass number minus 83.
Bismuth: quick answers
How many protons, neutrons and electrons does bismuth have?
Bismuth’s atomic number is 83, so every bismuth atom has 83 protons, and a neutral atom also has 83 electrons. Its most common natural isotope, bismuth-209, has 126 neutrons (other isotopes have different neutron counts).
What is the symbol for bismuth?
The chemical symbol for bismuth is Bi.
Is bismuth a solid, liquid or gas at room temperature?
Bismuth is a solid at room temperature (about 25 °C).
What family (group) is bismuth in?
Bismuth is a post-transition metal, in group 15, period 6 of the periodic table.
How many valence electrons does bismuth have?
Bismuth has 5 valence electrons, the electrons in its outer shell, which matches its position in group 15.
What is the electron configuration of bismuth?
The ground-state electron configuration of bismuth is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³.
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.
83 protons define bismuth.
The reference ground-state configuration frames atomic and chemical behavior.
Periodic position organizes recurring trends without replacing element-specific evidence.
The teaching nucleus is one isotope, not the relative atomic mass.
Phase claims preserve measured/evaluated/predicted/unknown evidence labels.
Bismuth in its period and family
Bismuth is the Period 6 Group 15 element below antimony. The 6s²6p³ outer pattern supports +3 and +5 chemistry, with the +3 state especially important for this heavy p-block element.
Bismuth Visual Lab
Explore Bi across the teaching nucleus, isolated-atom orbitals, evidence-aware material structure and temperature/evidence views, then connect those models to uses, isotopes and source-backed context.
Every mark points to one exact feature
The numbered markers explain the same information system used throughout Element Lookup. Unknown or predicted fields remain visibly labelled rather than being replaced with guesses.
Bismuth in one minute
Atomic number 83 means 83 protons.
Bismuth is a Group 15 post-transition metal, not a metalloid.
Ordinary bismuth has a rhombohedral A7 structure.
Natural bismuth is essentially ²⁰⁹Bi, an extraordinarily long-lived alpha emitter.
Bismuth compounds and elemental bismuth must be distinguished when discussing uses or safety.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 32 · 18 · 5 electrons
The 6s/6p views are isolated-atom probability models and do not reproduce the bands or bonding of rhombohedral bismuth.
Ordinary bismuth adopts the rhombohedral A7 structure. The viewer is a simplified rhombohedral teaching cell rather than a crystallographic coordinate file.. The viewer is evidence-aware: measured structures are identified as such; unknown bulk structures stay unknown.
Teaching visualization; not a literal finite sample or thermal trajectory.What this model does—and does not—show
The 6s/6p views are isolated-atom probability models and do not reproduce the bands or bonding of rhombohedral bismuth.
Where do I meet bismuth?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Low-melting alloys
Bismuth is used in fusible and low-melting alloy systems.
Rhombohedral heavy metal → ultra-slow alpha decay → compound/alloy uses
Bismuth overturns the old shorthand “heaviest stable element”: its sole natural isotope is radioactive, but on a timescale vastly longer than human history.
A7 bismuth
Bismuth is a brittle rhombohedral post-transition metal.
Antimony and bismuth: heavier pnictogens
Moving down Group 15 increases metallic character and strengthens inert-pair effects while the A7 structural family persists for Sb/Bi.
| Class | metalloid |
|---|---|
| Structure | A7 |
| Class | post-transition metal |
|---|---|
| Structure | A7 |
Bismuth properties: atomic, physical, thermal and chemical
Categories follow the science of this element rather than a fixed decorative template. Each row carries condition/provenance context and an evidence label; unknown values stay unknown.
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Atomic number | 83 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 208.980 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³ | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 15 · Period 6 · p-block | Periodic-table placement | Evaluated |
| Electronegativity | 1.9 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ²⁰⁹Bi | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Brittle silvery-white metal with a pinkish cast | Source-reviewed; see Sources below | Evaluated |
| Density | 9.79 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Rhombohedral · A7-type | Ordinary bismuth adopts the rhombohedral A7 structure. The viewer is a simplified rhombohedral teaching cell rather than a crystallographic coordinate file. | Measured |
| Classification | Post-transition metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Ordinary bismuth adopts the rhombohedral A7 structure. The viewer is a simplified rhombohedral teaching cell rather than a crystallographic coordinate file. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 544.556 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 1837 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, bismuth is solid below 544.556 K, liquid to about 1837 K, and gaseous above the boiling reference. | Shared phase registry drives the slider, regions and markers. | Evaluated |
| Condition warning | Temperature and pressure define phase behavior; purity/allotropy may matter. | Teaching condition statement | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Ordinary electrical behavior | Metallic conductor | Qualitative bulk behavior; exact resistivity depends on temperature, purity and alloy state. | Measured |
| Conduction model | Collective solid-state electrons | Do not interpret isolated-atom orbital clouds as literal current paths. | Reviewed |
| Surface / compound caveat | Oxides, salts and alloys can behave differently from the pure metal | Material context | Reviewed |
| Engineering values | Condition-dependent | Use condition-specific materials data for engineering calculations. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Common oxidation states | +3, +5 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Bi³⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Bismuth is the Period 6 Group 15 element below antimony. The 6s²6p³ outer pattern supports +3 and +5 chemistry, with the +3 state especially important for this heavy p-block element. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ²⁰⁹Bi | Extremely long-lived natural alpha emitter | Essentially all natural bismuth; half-life is of order 10¹⁹ years. | Evaluated |
| Bismuth radioisotopes | Synthetic radioactive isotopes | Shorter-lived isotopes are used in nuclear research. | Evaluated |
| Evidence lesson | Radioactive does not mean highly active | Half-life and isotope abundance determine activity. | Evaluated |
| Teaching nucleus | ²⁰⁹Bi · 83 protons + 126 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Bismuth a solid, liquid or gas? State at temperature
At approximately standard pressure, bismuth is solid below 544.556 K, liquid to about 1837 K, and gaseous above the boiling reference.
Where on Earth is Bismuth found or produced?
Who discovered Bismuth, and when?
Bismuth-containing materials were known long before the element was clearly distinguished from lead and tin.
Claude François Geoffroy is commonly credited with demonstrating bismuth as distinct from lead.
High-purity bismuth and compounds gained specialized metallurgical and pharmaceutical roles.
Alpha decay of ²⁰⁹Bi was directly observed, establishing its extremely long half-life.
From by-product metal to bismuth materials: high-level path
Bismuth is commonly obtained as a by-product of processing lead, copper, tin or other ores rather than from a single universal dedicated ore route.
Refining separates bismuth into metal or compound feedstocks.
Manufacturing uses bismuth in alloys, compounds and specialty materials.
Recycling can recover bismuth from selected industrial streams.
What is bismuth used for?
Fusible alloys
Bismuth helps produce low-melting alloys for specialized thermal and safety devices.
Medicinal chemistry
Certain bismuth compounds are used in gastrointestinal medicines.
Metallurgy
Bismuth can modify machinability and serve in selected lead-substitution alloys.
Materials research
Its unusual electronic and thermoelectric behavior makes bismuth important in condensed-matter research.
Bismuth isotopes and natural abundance
²⁰⁹Bi
Extremely long-lived natural alpha emitterEssentially all natural bismuth; half-life is of order 10¹⁹ years.
Bismuth radioisotopes
Synthetic radioactive isotopesShorter-lived isotopes are used in nuclear research.
Evidence lesson
Radioactive does not mean highly activeHalf-life and isotope abundance determine activity.
Five-question Bismuth check
What is bismuth’s atomic number?
Is natural bismuth radioactive?
What is its ordinary crystal class?
Which oxidation state is especially common?
What causes many rainbow crystal colors?
Bismuth questions students commonly ask
Each answer starts with the direct fact, then explains the chemistry, evidence or material context so the result is understandable rather than merely memorized.
What is bismuth?
Short answer: Bismuth is chemical element 83, a heavy post-transition metal.
Atomic number 83 means every bismuth nucleus contains 83 protons. In the periodic table, Bismuth is classified here as a post-transition metal in Period 6 and Group 15. Bismuth is the Period 6 Group 15 element below antimony. The 6s²6p³ outer pattern supports +3 and +5 chemistry, with the +3 state especially important for this heavy p-block element.
Key point: Bi is element 83; its periodic position and electron structure explain the rest of the page.
Is bismuth a metal?
Short answer: Yes. It is a post-transition metal in Group 15.
This guide classifies Bismuth as a post-transition metal. Its periodic position is Period 6, p-block, Group 15. Bismuth is the Period 6 Group 15 element below antimony. The 6s²6p³ outer pattern supports +3 and +5 chemistry, with the +3 state especially important for this heavy p-block element.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
Is bismuth radioactive?
Short answer: Yes in a precise nuclear sense: natural ²⁰⁹Bi alpha-decays, but its half-life is around 2 × 10¹⁹ years, so its activity is extremely low.
²⁰⁹Bi: Extremely long-lived natural alpha emitter: Essentially all natural bismuth; half-life is of order 10¹⁹ years. Bismuth radioisotopes: Synthetic radioactive isotopes: Shorter-lived isotopes are used in nuclear research.
Key point: Radioactivity is isotope-specific; do not apply one isotope’s nuclear behavior to every atom of the element.
What is bismuth used for?
Short answer: Uses include low-melting alloys, selected medicinal compounds, metallurgy and specialized materials.
Fusible alloys: Bismuth helps produce low-melting alloys for specialized thermal and safety devices. Medicinal chemistry: Certain bismuth compounds are used in gastrointestinal medicines. “Is bismuth radioactive?” needs a precise answer. Natural bismuth is essentially all ²⁰⁹Bi, which undergoes alpha decay with a half-life around 2 × 10¹⁹ years. That makes it radioactive in nuclear physics, while its activity is extraordinarily low in ordinary material.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
What is the symbol for bismuth?
Short answer: Bi.
The symbol Bi is the standardized chemical abbreviation for element 83. In a chemical formula, Bi identifies bismuth atoms; a compound containing Bi is not automatically the same material as elemental bismuth.
Key point: Bi always identifies element 83.
How many protons does bismuth have?
Short answer: Bismuth has 83 protons, because its atomic number is 83.
Every bismuth isotope has 83 protons. A neutral bismuth atom has 83 electrons. The naturally occurring isotope bismuth-209 has 209 − 83 = 126 neutrons; its extraordinarily long alpha-decay half-life is explained elsewhere on this page.
Key point: 83 protons identify bismuth; the isotope determines the neutron count.
Why are bismuth crystals colorful?
Short answer: The familiar rainbow appearance usually comes from thin oxide films on grown bismuth crystals, not from the intrinsic bulk color alone.
The ordinary elemental-material description used here is: Brittle silvery-white metal with a pinkish cast. Crystal growth Slow solidification can produce colorful oxide-coated hopper crystals, a visual consequence of growth geometry and thin surface films.
Key point: Elemental appearance can differ from the colors of its ions, compounds, oxide films or host materials.
Scientific sources for Bismuth
- Royal Society of Chemistry - Bismuth
- NIST - Atomic Weights / Bismuth
- USGS - Mineral Commodity Summaries 2026
Questions to ask next about Bismuth
A good element lesson should lead to the next useful question, not end after a list of facts.
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