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.
Lutetium (Lu)
Lutetium is element 71. This guide connects its periodic-table identity to evidence-aware structure, isotopes, uses, discovery and the search questions learners actually ask.
Lutetium atomic number, mass, electron configuration and key properties
Lutetium: quick answers
How many protons, neutrons and electrons does lutetium have?
Lutetium’s atomic number is 71, so every lutetium atom has 71 protons, and a neutral atom also has 71 electrons. Its most common natural isotope, lutetium-175, has 104 neutrons (other isotopes have different neutron counts).
What is the symbol for lutetium?
The chemical symbol for lutetium is Lu.
Is lutetium a solid, liquid or gas at room temperature?
Lutetium is a solid at room temperature (about 25 °C).
What family (group) is lutetium in?
Lutetium is a lanthanide, in group 3, period 6 of the periodic table.
What is the electron configuration of lutetium?
The ground-state electron configuration of lutetium is [Xe] 4f¹⁴ 5d¹ 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.
71 protons define lutetium.
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.
Lutetium in its period and family
Lutetium is element 71 in Period 6. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Lutetium Visual Lab
Explore Lu 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.
Lutetium in one minute
Atomic number 71 means every lutetium nucleus has 71 protons.
The ground-state/reference electron configuration is [Xe] 4f¹⁴ 5d¹ 6s².
The representative teaching isotope is ¹⁷⁵Lu.
Lutetium closes the lanthanide sequence. Search results often mix elemental Lu with lutetium-containing scintillator crystals and medical compounds, so the guide keeps the element separate from its engineered materials.
Material structure status: Hexagonal close-packed (HCP).
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 32 · 9 · 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 Lutetium. 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 lutetium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Catalysts in selected petroleum chemistry
This context uses Lutetium or a lutetium-containing material; the element and its compounds/isotopes are kept distinct.
Lutetium 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 Lutetium uses the reviewed ordinary structure shown in the Visual Lab.
Lutetium in periodic context
Compare nearby or family-related elements without treating a periodic trend as a substitute for element-specific evidence.
| Atomic number | 70 |
|---|---|
| Context | neighbor / series |
| Atomic number | 71 |
|---|---|
| Context | neighbor / series |
| Atomic number | 72 |
|---|---|
| Context | neighbor / series |
Lutetium 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 | 71 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 174.967 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 4f¹⁴ 5d¹ 6s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group Lanthanide · Period 6 · f-block | Periodic-table placement | Evaluated |
| Electronegativity | 1.27 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ¹⁷⁵Lu | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Silvery-white, hard, dense lanthanide metal | Source-reviewed; see Sources below | Evaluated |
| Density | 9.84 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 Lutetium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | Measured |
| Classification | Lanthanide | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | The viewer represents the reviewed Hexagonal close-packed (HCP) material reference for elemental Lutetium. 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 | 1936 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 3675 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, lutetium is treated as solid below 1936 K, liquid between the melting and boiling references, and gas above 3675 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 |
|---|---|---|---|
| Common oxidation states | +3 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Lu³⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Lutetium is element 71 in Period 6. Its f-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 |
|---|---|---|---|
| ¹⁷⁵Lu | 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 | ¹⁷⁵Lu · 71 protons + 104 neutrons | Reference isotope used in the nucleus model | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Page evidence note | Atomic identity and source-reviewed reference values are separated from predictions. Search demand shapes headings and FAQs but never overrides scientific evidence; unknown bulk structure/density/phase values remain visibly unknown. | Evidence summary for this guide | Reviewed |
| Structure evidence | The viewer represents the reviewed Hexagonal close-packed (HCP) material reference for elemental Lutetium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | 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 | 3 primary/reference links listed below | Open the Sources section for the actual references. | Reviewed |
Is Lutetium a solid, liquid or gas? State at temperature
At approximately standard pressure, lutetium is treated as solid below 1936 K, liquid between the melting and boiling references, and gas above 3675 K. Solid-state allotropy is only shown where explicitly reviewed.
Where on Earth is Lutetium found or produced?
Who discovered Lutetium, and when?
Georges Urbain reported the separation of lutetium in Paris; Charles James independently obtained the element around the same period.
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 Lutetium applications: high-level material path
Lutetium 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 lutetium used for?
Catalysts in selected petroleum chemistry
Element-specific use context; compounds/alloys are distinguished from pure metal.
Lu-containing scintillator crystals in radiation detection and medical imaging
Element-specific use context; compounds/alloys are distinguished from pure metal.
Research and specialized materials
Element-specific use context; compounds/alloys are distinguished from pure metal.
Lutetium isotopes and natural abundance
¹⁷⁵Lu
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 Lutetium check
What is Lutetium’s atomic number?
Which statement best describes the material evidence for Lutetium?
What is the safest rule for Lutetium uses?
Lutetium 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 lutetium?
Short answer: Lutetium is chemical element 71, symbol Lu, classified here as lanthanide.
Atomic number 71 means every lutetium nucleus contains 71 protons. In the periodic table, Lutetium is classified here as a lanthanide in Period 6 and Group Lanthanide. Lutetium is element 71 in Period 6. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Key point: Lu is element 71; its periodic position and electron structure explain the rest of the page.
What is the atomic number of lutetium?
Short answer: The atomic number is 71, meaning every lutetium nucleus has 71 protons.
Atomic number is defined by proton count, so 71 protons are what make an atom lutetium. A neutral lutetium atom also has 71 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
What is the symbol for lutetium?
Short answer: The chemical symbol is Lu.
The symbol Lu is the standardized chemical abbreviation for element 71. In a chemical formula, Lu identifies lutetium atoms; a compound containing Lu is not automatically the same material as elemental lutetium.
Key point: Lu always identifies element 71.
What is lutetium used for?
Short answer: Lutetium has limited uses, including selected catalysts and lutetium-containing scintillator crystals used in radiation-detection and imaging systems.
Catalysts in selected petroleum chemistry: Element-specific use context; compounds/alloys are distinguished from pure metal. Lu-containing scintillator crystals in radiation detection and medical imaging: Element-specific use context; compounds/alloys are distinguished from pure metal. Lutetium closes the lanthanide sequence. Search results often mix elemental Lu with lutetium-containing scintillator crystals and medical compounds, so the guide keeps the element separate from its engineered materials.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Is lutetium a metal?
Short answer: Yes. Lutetium is a dense silvery lanthanide metal.
This guide classifies Lutetium as a lanthanide. Its periodic position is Period 6, f-block, Group Lanthanide. Lutetium is element 71 in Period 6. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
Where is lutetium on the periodic table?
Short answer: Lutetium is element 71 at the end of the lanthanide series in Period 6; many tables place it with Group 3.
Lutetium is element 71. This guide connects its periodic-table identity to evidence-aware structure, isotopes, uses, discovery and the search questions learners actually ask. Lutetium is element 71 in Period 6. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Key point: Use the direct answer together with the material, isotope and evidence context shown elsewhere on the page.
Scientific sources for Lutetium
- Royal Society of Chemistry - Lutetium
- NIST - Atomic Weights and Isotopic Compositions
- IUPAC - Periodic Table of Elements
Questions to ask next about Lutetium
A good element lesson should lead to the next useful question, not end after a list of facts.
Found an error, something unclear, or a missing topic?
Tell us what you noticed. Feedback goes to a private review queue and is never published automatically.