Element / isotope identity
Atomic number, isotope identity and discovery evidence are experimentally/evaluatively grounded.
Electron configuration
Very-heavy-element configurations are theory/evaluation-led; ordinary elements use evaluated ground-state references.
Bulk material structure
The Hexagonal close-packed (HCP) reference is represented by a simplified teaching cell.
Phase / density data
Unknown values stay unknown; reported values are tied to the elemental material reference.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Osmium (Os)
Osmium is element 76. This guide connects its periodic-table identity to evidence-aware structure, isotopes, uses, discovery and the search questions learners actually ask.
Osmium atomic number, mass, electron configuration and key properties
Osmium: quick answers
How many protons, neutrons and electrons does osmium have?
Osmium’s atomic number is 76, so every osmium atom has 76 protons, and a neutral atom also has 76 electrons. Its most common natural isotope, osmium-192, has 116 neutrons (other isotopes have different neutron counts).
What is the symbol for osmium?
The chemical symbol for osmium is Os.
Is osmium a solid, liquid or gas at room temperature?
Osmium is a solid at room temperature (about 25 °C).
What family (group) is osmium in?
Osmium is a transition metal, in group 8, period 6 of the periodic table.
What is the electron configuration of osmium?
The ground-state electron configuration of osmium is [Xe] 4f¹⁴ 5d⁶ 6s².
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.
76 protons define osmium.
Ground-state/reference configuration frames atomic behavior; heavy-element predictions remain evidence-labelled.
Periodic position organizes trends without replacing element-specific evidence.
The teaching nucleus is one isotope, not the relative atomic mass.
Measured structures are visualized; unknown bulk structures stay unknown.
Osmium in its period and family
Osmium is element 76 in Period 6. Its d-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Osmium Visual Lab
Explore Os across the teaching nucleus, isolated-atom orbitals, evidence-aware material structure and temperature/evidence views, then connect those models to uses, isotopes, search-led questions 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.
Osmium in one minute
Atomic number 76 means every osmium nucleus has 76 protons.
The ground-state/reference electron configuration is [Xe] 4f¹⁴ 5d⁶ 6s².
The representative teaching isotope is ¹⁹²Os.
Osmium is famous for extreme density, but the most important safety distinction is chemical form: elemental Os metal is not the same substance as volatile, hazardous OsO₄.
Material structure status: Hexagonal close-packed (HCP).
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 32 · 14 · 2 electrons
Displayed orbitals are isolated-atom, nonrelativistic teaching probability models. They are not bulk-band structures, bonding orbitals or direct measured electron-density maps; relativistic effects become especially important for very heavy elements.
The viewer represents the reviewed Hexagonal close-packed (HCP) material reference for elemental Osmium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound.. 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
Displayed orbitals are isolated-atom, nonrelativistic teaching probability models. They are not bulk-band structures, bonding orbitals or direct measured electron-density maps; relativistic effects become especially important for very heavy elements.
Where do I meet osmium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Very hard wear-resistant alloys
This context uses Osmium or a osmium-containing material; the element and its compounds/isotopes are kept distinct.
Osmium metal → engineered materials → evidence boundary
The same element can appear in very different materials; the page keeps elemental structure separate from compounds, alloys and isotope-specific applications.
Hexagonal close-packed (HCP)
Elemental Osmium uses the reviewed ordinary structure shown in the Visual Lab.
Osmium in periodic context
Compare nearby or family-related elements without treating a periodic trend as a substitute for element-specific evidence.
| Atomic number | 75 |
|---|---|
| Context | neighbor / series |
| Atomic number | 76 |
|---|---|
| Context | neighbor / series |
| Atomic number | 77 |
|---|---|
| Context | neighbor / series |
Osmium 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 | 76 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 190.23 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 4f¹⁴ 5d⁶ 6s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 8 · Period 6 · d-block | Periodic-table placement | Evaluated |
| Electronegativity | 2.20 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ¹⁹²Os | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Shiny silver, exceptionally dense platinum-group metal | Source-reviewed; see Sources below | Evaluated |
| Density | 22.5872 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Hexagonal close-packed (HCP) | The viewer represents the reviewed Hexagonal close-packed (HCP) material reference for elemental Osmium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | Measured |
| Classification | Transition metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | The viewer represents the reviewed Hexagonal close-packed (HCP) material reference for elemental Osmium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 3306 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 5281 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, osmium is treated as solid below 3306 K, liquid between the melting and boiling references, and gas above 5281 K. Solid-state allotropy is only shown where explicitly reviewed. | 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 | +8, +6, +4, +3, +2, 0 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Os³⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Osmium is element 76 in Period 6. Its d-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ¹⁹²Os | Reference teaching isotope | Mass number belongs to a specific isotope and is not the same thing as relative atomic mass. | Evaluated |
| Isotope evidence | Element-specific nuclear context | Half-life and decay properties are isotope-specific; the page does not generalize one isotope to all atoms. | Evaluated |
| Teaching nucleus | ¹⁹²Os · 76 protons + 116 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Osmium a solid, liquid or gas? State at temperature
At approximately standard pressure, osmium is treated as solid below 3306 K, liquid between the melting and boiling references, and gas above 5281 K. Solid-state allotropy is only shown where explicitly reviewed.
Where on Earth is Osmium found or produced?
Who discovered Osmium, and when?
Smithson Tennant identified osmium in residues left after dissolving platinum ores in London.
The element name and discovery story are part of the historical record; search-led questions are answered without turning history into scientific evidence for bulk properties.
Current use is described at the level supported by the element’s availability and evidence, with research-only elements kept research-only.
From source material to Osmium applications: high-level material path
Osmium enters supply chains through ores, by-products or specialized refining routes rather than through the educational structure shown here.
Industrial separation/refining produces metal or element-specific compounds; this guide does not provide operational extraction recipes.
The refined material is converted into the particular alloy, compound, device or catalyst needed by the application.
Recycling and recovery depend on host material and economics; application materials must not be confused with pure element.
What is osmium used for?
Very hard wear-resistant alloys
Element-specific use context; compounds/alloys are distinguished from pure metal.
Specialized electrical contacts and instrument pivots
Element-specific use context; compounds/alloys are distinguished from pure metal.
Catalytic chemistry in selected applications
Element-specific use context; compounds/alloys are distinguished from pure metal.
Osmium isotopes and natural abundance
¹⁹²Os
Reference teaching isotopeMass number belongs to a specific isotope and is not the same thing as relative atomic mass.
Isotope evidence
Element-specific nuclear contextHalf-life and decay properties are isotope-specific; the page does not generalize one isotope to all atoms.
Five-question Osmium check
What is Osmium’s atomic number?
Which statement best describes the material evidence for Osmium?
What is the safest rule for Osmium uses?
Osmium 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 osmium?
Short answer: Osmium is chemical element 76, symbol Os, classified here as transition metal.
Atomic number 76 means every osmium nucleus contains 76 protons. In the periodic table, Osmium is classified here as a transition metal in Period 6 and Group 8. Osmium is element 76 in Period 6. Its d-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Key point: Os is element 76; its periodic position and electron structure explain the rest of the page.
What is the atomic number of osmium?
Short answer: The atomic number is 76, meaning every osmium nucleus has 76 protons.
Atomic number is defined by proton count, so 76 protons are what make an atom osmium. A neutral osmium atom also has 76 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
What is the symbol for osmium?
Short answer: The chemical symbol is Os.
The symbol Os is the standardized chemical abbreviation for element 76. In a chemical formula, Os identifies osmium atoms; a compound containing Os is not automatically the same material as elemental osmium.
Key point: Os always identifies element 76.
Why is osmium so dense?
Short answer: Osmium has an exceptionally high room-temperature density, about 22.59 g/cm³ in the cited reference data.
Osmium is famous for extreme density, but the most important safety distinction is chemical form: elemental Os metal is not the same substance as volatile, hazardous OsO₄.
Key point: The mechanism matters: connect the observed behavior to electron structure, bonding, phase or the specific material form rather than memorizing the result alone.
What is osmium used for?
Short answer: Uses are limited and specialized, including hard alloys, contacts, pivots and some catalytic chemistry.
Very hard wear-resistant alloys: Element-specific use context; compounds/alloys are distinguished from pure metal. Specialized electrical contacts and instrument pivots: Element-specific use context; compounds/alloys are distinguished from pure metal. Osmium is famous for extreme density, but the most important safety distinction is chemical form: elemental Os metal is not the same substance as volatile, hazardous OsO₄.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Is osmium toxic?
Short answer: Risk depends on chemical form. Osmium tetroxide is a highly hazardous volatile compound and must not be treated as equivalent to bulk osmium metal.
Osmium hazards depend strongly on chemical form; volatile osmium tetroxide requires compound-specific safety information.
Key point: Safety claims must be substance- and exposure-specific.
Scientific sources for Osmium
- Royal Society of Chemistry - Osmium
- NIST - Atomic Weights and Isotopic Compositions
- IUPAC - Periodic Table of Elements
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