Element identity
Atomic number, periodic identity and reference mass/isotope conventions are established and source-reviewed.
Atomic / electronic model
Atomic configurations and orbital teaching models are reference interpretations; heavy-element electronic structure is more complex than a classical shell picture.
Nuclear / isotope data
Half-lives, isotope identities and decay information are taken from evaluated nuclear-data/reference sources and remain isotope-specific.
Material / phase data
Ordinary bulk and phase values are shown only where defensible; solid-state transitions are kept separate from melting.
Geography / safety boundary
Occurrence, discovery and public research context may be mapped. Operational radioactive-material inventories, access routes and sensitive facility details are intentionally not mapped.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Polonium (Po)
Polonium is element 84, a rare radioactive chalcogen famous for two very different reasons: Marie Curie named it for Poland, and α-polonium is the textbook elemental example of a simple-cubic crystal. Its isotope science also demonstrates how nuclear decay can generate heat in matter.
Polonium atomic number, mass, electron configuration and key properties
Polonium: quick answers
How many protons, neutrons and electrons does polonium have?
Polonium’s atomic number is 84, so every polonium atom has 84 protons, and a neutral atom also has 84 electrons. Polonium has no stable isotopes, so the number of neutrons depends on which isotope you mean.
What is the symbol for polonium?
The chemical symbol for polonium is Po.
Is polonium a solid, liquid or gas at room temperature?
Polonium is a solid at room temperature (about 25 °C).
What family (group) is polonium in?
Polonium is a post-transition metal, in group 16, period 6 of the periodic table.
How many valence electrons does polonium have?
Polonium has 6 valence electrons, the electrons in its outer shell, which matches its position in group 16.
What is the electron configuration of polonium?
The ground-state electron configuration of polonium is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴.
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.
Eighty-four protons define polonium.
Its outer pattern places polonium in Group 16.
Polonium lies below tellurium.
Po-210 is a well-known strong alpha emitter.
Polonium is the classic elemental simple-cubic structure example.
Polonium in its period and family
Polonium is in Group 16, Period 6 below tellurium. Periodic chemistry links it to the chalcogens, but strong radioactivity and relativistic effects make heavy-element evidence especially important.
Polonium Visual Lab
Decode polonium’s tile, rotate a ²¹⁰Po teaching nucleus and simple-cubic α-Po cell, inspect 6s/6p probability models, and connect crystal allotropy, alpha decay, discovery history and evidence-aware safety.
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.
Polonium in one minute
Atomic number 84 means every polonium nucleus contains 84 protons.
Polonium has no stable isotopes.
α-polonium is simple cubic, an unusually rare crystal structure among elements.
On heating, α-Po transforms to rhombohedral β-Po with substantial hysteresis reported for the transition.
Polonium was discovered by Marie and Pierre Curie and named for Poland.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 32 · 18 · 6 electrons
The 6s and 6p clouds are isolated-atom probability models. They do not depict alpha particles or radioactive decay; decay originates in the nucleus.
α-Po is the classic simple-cubic elemental crystal. On heating, β-Po is rhombohedral; the α↔β transition shows hysteresis, so a single exact reversible threshold would be misleading.. 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 and 6p clouds are isolated-atom probability models. They do not depict alpha particles or radioactive decay; decay originates in the nucleus.
Where do I meet polonium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Simple-cubic crystal
α-Po is a striking crystallography example because atoms occupy a simple-cubic lattice near room temperature.
Simple cubic crystal + alpha-decay self-heating
Polonium combines a rare lattice with intense nuclear behavior, and the two phenomena come from different parts of the atom.
Simple-cubic solid
Near room temperature alpha-polonium is the classic elemental simple-cubic crystal.
Selenium, tellurium and polonium
The chalcogen valence pattern continues down the group while metallic character and heavy-atom effects increase.
| Valence | 4s² 4p⁴ |
|---|---|
| Context | multiple allotropes |
| Valence | 5s² 5p⁴ |
|---|---|
| Context | metalloid-like solid |
| Valence | 6s² 6p⁴ |
|---|---|
| Crystal | α-Po simple cubic |
| Stable isotopes | none |
Polonium 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 | 84 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | [209] | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴ | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 16 · Period 6 · p-block | Periodic-table placement | Evaluated |
| Electronegativity | 2.0 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ²¹⁰Po | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Radioactive solid at 20 °C | Source-reviewed; see Sources below | Evaluated |
| Density | 9.20 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | α-polonium · simple cubic near room temperature | α-Po is the classic simple-cubic elemental crystal. On heating, β-Po is rhombohedral; the α↔β transition shows hysteresis, so a single exact reversible threshold would be misleading. | Measured |
| Classification | Radioactive chalcogen | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | α-Po is the classic simple-cubic elemental crystal. On heating, β-Po is rhombohedral; the α↔β transition shows hysteresis, so a single exact reversible threshold would be misleading. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 527 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 1235 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | A teaching path for polonium shows α-Po simple-cubic solid at lower temperature, a β-Po rhombohedral solid region before melting, liquid to the boiling reference, and gas above. The α↔β transition is hysteretic, so the marker is an approximate heating reference rather than a perfectly reversible equilibrium switch. | 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 |
|---|---|---|---|
| Common oxidation states | +2 and +4 common · +6 also reported | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Po²⁺ / Po⁴⁺ context | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Polonium is in Group 16, Period 6 below tellurium. Periodic chemistry links it to the chalcogens, but strong radioactivity and relativistic effects make heavy-element evidence especially important. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ²¹⁰Po | Radioactive · half-life about 138 days | A well-known strong alpha emitter and the teaching nucleus used on this page. | Evaluated |
| ²⁰⁹Po | Radioactive · long-lived on human time scales | Often used as the bracketed mass-number reference in periodic-table data for polonium. | Evaluated |
| Polonium isotope family | No stable isotopes | All polonium isotopes are radioactive; nuclear identity is essential to any property discussion. | Evaluated |
| Teaching nucleus | ²¹⁰Po · 84 protons + 126 neutrons | Reference isotope used in the nucleus model | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Page evidence note | Atomic identity, radioactivity and α-Po simple-cubic structure are measured/evaluated. The α↔β transition is represented with an approximate heating threshold and an explicit hysteresis warning. No operational radiological instructions are provided. | Evidence summary for this guide | Reviewed |
| Structure evidence | α-Po is the classic simple-cubic elemental crystal. On heating, β-Po is rhombohedral; the α↔β transition shows hysteresis, so a single exact reversible threshold would be misleading. | Measured structure, labelled schematic, prediction or explicit unknown as applicable. | Reviewed |
| Map evidence rule | Real pins are reviewed examples; conceptual layers are used when pins would mislead. | Geography Explorer 2.0 | Reviewed |
| Source set | 4 primary/reference links listed below | Open the Sources section for the actual references. | Reviewed |
Is Polonium a solid, liquid or gas? State at temperature
A teaching path for polonium shows α-Po simple-cubic solid at lower temperature, a β-Po rhombohedral solid region before melting, liquid to the boiling reference, and gas above. The α↔β transition is hysteretic, so the marker is an approximate heating reference rather than a perfectly reversible equilibrium switch.
Where on Earth is Polonium found or produced?
Who discovered Polonium, and when?
Marie and Pierre Curie announced evidence for a new radioactive element in pitchblende residues and named it polonium.
Radioactivity research established polonium as an intense alpha emitter and clarified its place in decay chains.
Polonium isotopes were studied for nuclear physics and specialized heat-source applications under strict controls.
Polonium remains primarily a research and radiological-safety subject rather than a commercial bulk material.
How polonium is studied: evidence and safety, not extraction instructions
Natural polonium appears only in trace quantities as members of radioactive decay chains.
Polonium isotopes can also be produced in specialized nuclear facilities, but operational production details are intentionally outside this guide.
Scientific measurements focus on decay, isotope identity, crystal structure and chemistry using controlled radiological methods.
Element Lookup provides no sourcing, separation, concentration or handling procedures for polonium.
What is polonium used for?
Nuclear research
Polonium isotopes are studied as alpha emitters and as part of radioactive decay-chain physics.
Historical antistatic devices
Po-210 was used in some historical static eliminators, an application largely replaced by safer technologies.
Specialized heat-source history
The heat from alpha decay has been used in specialized historical contexts; this is not a consumer-use recommendation.
Crystallography education
α-Po is a memorable example of the simple-cubic lattice.
Polonium isotopes and natural abundance
²¹⁰Po
Radioactive · half-life about 138 daysA well-known strong alpha emitter and the teaching nucleus used on this page.
²⁰⁹Po
Radioactive · long-lived on human time scalesOften used as the bracketed mass-number reference in periodic-table data for polonium.
Polonium isotope family
No stable isotopesAll polonium isotopes are radioactive; nuclear identity is essential to any property discussion.
Five-question Polonium check
What is polonium’s atomic number?
What is special about α-polonium’s crystal structure?
What was polonium named after?
Does polonium have stable isotopes?
Why is the α↔β transition shown with a caveat?
Polonium 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.
Is polonium a metal?
Short answer: Polonium is commonly described as a metallic or metalloid-like heavy chalcogen; its elemental solid has metallic characteristics, but classification language varies across references.
This guide classifies Polonium as a radioactive chalcogen. Its periodic position is Period 6, p-block, Group 16. Polonium is in Group 16, Period 6 below tellurium. Periodic chemistry links it to the chalcogens, but strong radioactivity and relativistic effects make heavy-element evidence especially important.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
What is polonium’s atomic number?
Short answer: 84.
Atomic number is defined by proton count, so 84 protons are what make an atom polonium. A neutral polonium atom also has 84 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
What was polonium named after?
Short answer: Poland, Marie Curie’s homeland.
In 1898, Marie and Pierre Curie announced evidence for a new radioactive element in pitchblende residues and named it polonium.
Key point: Element names record scientific history; the name itself does not determine the element’s chemistry.
Where was polonium discovered?
Short answer: Marie and Pierre Curie discovered it in Paris in 1898 while studying pitchblende.
In 1898, Marie and Pierre Curie announced evidence for a new radioactive element in pitchblende residues and named it polonium. In the early 20th century, Radioactivity research established polonium as an intense alpha emitter and clarified its place in decay chains.
Key point: Discovery location/history is different from natural occurrence or modern production geography.
What crystal structure does alpha-polonium have?
Short answer: Simple cubic, one of the rarest elemental crystal structures.
α-Po is the classic simple-cubic elemental crystal. On heating, β-Po is rhombohedral; the α↔β transition shows hysteresis, so a single exact reversible threshold would be misleading. The Structure viewer is an evidence-aware teaching model: measured or defensible structures are shown as models, while genuinely unknown bulk structures remain explicitly unknown.
Key point: A teaching lattice is a scientific model, not a photograph of a finite chunk of material.
What is polonium used for?
Short answer: Modern use is limited and specialized, mainly scientific; historical applications included antistatic devices and heat-source contexts.
Nuclear research: Polonium isotopes are studied as alpha emitters and as part of radioactive decay-chain physics. Historical antistatic devices: Po-210 was used in some historical static eliminators, an application largely replaced by safer technologies. Polonium’s simple-cubic lattice is a materials-science curiosity; its radioactivity is a nuclear property. Neither fact makes polonium suitable for ordinary handling.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Is polonium radioactive?
Short answer: Yes. All known polonium isotopes are radioactive; polonium-210 is a well-known alpha-emitting isotope.
²¹⁰Po: Radioactive · half-life about 138 days: A well-known strong alpha emitter and the teaching nucleus used on this page. ²⁰⁹Po: Radioactive · long-lived on human time scales: Often used as the bracketed mass-number reference in periodic-table data for polonium.
Key point: Radioactivity is isotope-specific; do not apply one isotope’s nuclear behavior to every atom of the element.
Scientific sources for Polonium
- Royal Society of Chemistry - Polonium
- NIST - Atomic Data for Polonium
- AFLOW - Polonium crystal structures
- Nobel Prize - Marie Curie biographical/discovery context
Questions to ask next about Polonium
A good element lesson should lead to the next useful question, not end after a list of facts.
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