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Free Holmium student datasheetPrintable revision sheet with identity, structure, evidence notes, phase behavior, uses, isotopes and review prompts.
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Holmium atomic number, mass, electron configuration and key properties

Atomic number
67
Relative atomic mass
164.930
Electron configuration
[Xe] 4f¹¹ 6s²
Common oxidation states
+3
Density
8.80 g/cm³
Melting point
1745 K
Boiling point
2973 K
Ordinary crystal
Hexagonal close-packed (HCP)
ClassificationLanthanide
Reference isotope¹⁶⁵Ho
State contextBright silvery lanthanide metal
Evidence noteAtomic identity and reference values are source-reviewed. Material viewers are teaching representations, not crystallographic refinements. Search demand shapes headings and FAQs but never overrides measured/evaluated evidence or element-versus-compound distinctions.
Quick answers

Holmium: quick answers

How many protons, neutrons and electrons does holmium have?

Holmium’s atomic number is 67, so every holmium atom has 67 protons, and a neutral atom also has 67 electrons. Its most common natural isotope, holmium-165, has 98 neutrons (other isotopes have different neutron counts).

What is the symbol for holmium?

The chemical symbol for holmium is Ho.

Is holmium a solid, liquid or gas at room temperature?

Holmium is a solid at room temperature (about 25 °C).

What family (group) is holmium in?

Holmium is a lanthanide, in period 6 (the f-block row shown below the main table) of the periodic table.

What is the electron configuration of holmium?

The ground-state electron configuration of holmium is [Xe] 4f¹¹ 6s².

Connect the facts

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.

Common misconceptionHolmium can be strongly magnetic, but a “holmium laser” uses Ho ions doped into a host crystal; the laser medium is not a bar of elemental Ho. Nuclear and optical applications are likewise material- or isotope-specific.
Periodic-table position

Holmium in its period and family

Holmium is a late lanthanide with [Xe]4f¹¹6s² ground state and dominant Ho³⁺ chemistry. Its partially filled 4f shell gives a very large atomic magnetic moment.

Interactive Visual Lab

Holmium Visual Lab

Explore Ho 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.

Overview · structure · orbitals · real world
How to read an element tile

Every mark points to one exact feature

167 2164.930 3Ho 4[Xe] 4f¹¹ 6s² 5Holmium 6Hexagonal close-packed (HCP) 7Bright silvery la…
1Atomic numberNumber of protons
2Relative atomic massStandard value or bracketed reference mass
3Chemical symbolHo
4Electron configurationGround-state shorthand or evidence-labelled prediction
5Element nameHolmium
6Structure contextHexagonal close-packed (HCP)
7Physical-state contextBright silvery lanthanide metal

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.

Five things worth remembering

Holmium in one minute

01

Atomic number 67 means every holmium nucleus has 67 protons.

02

Neutral Holmium has the ground-state configuration [Xe] 4f¹¹ 6s².

03

The representative teaching isotope is ¹⁶⁵Ho.

04

Holmium can be strongly magnetic, but a “holmium laser” uses Ho ions doped into a host crystal; the laser medium is not a bar of elemental Ho.

05

The ordinary material reference is Hexagonal close-packed (HCP).

Atomic structure teaching model

¹⁶⁵Ho nucleus · neutral Ho

Nucleus modelNucleon-count teaching view
67 p⁺ + 98 n⁰¹⁶⁵Ho · schematic nucleus, not a literal nuclear geometry
Electron-count schematicPrincipal-shell populations

Shell rings organize electron counts. They are not electron trajectories or orbital shapes.

Nucleus, shell count and material structure are deliberately separated so one picture is not mistaken for another.
Connect picture → chemistry

2 · 8 · 18 · 29 · 8 · 2 electrons

n=12
n=28
n=318
n=429
n=58
n=62
Why this electron pattern matters

The displayed 4f_xyz orbital is one representative real f cubic harmonic. It is not a picture of the whole 4f subshell or the electronic bands in the bulk material.

Teaching boundary: the nucleus uses colored spheres to make proton/neutron counts visible; the shell diagram only summarizes principal-shell populations. Neither is a literal picture of electron motion.
Material / molecular structure viewer

Hexagonal close-packed (HCP)

Ordinary holmium metal is HCP. Optical laser hosts and holmium-containing magnets have different structures from the elemental metal.
Hexagonal close-packed (HCP)Ordinary holmium metal is HCP. Optical laser hosts and holmium-containing magnets have different structures from the elemental metal.
What are you seeing?

Ordinary holmium metal is HCP. Optical laser hosts and holmium-containing magnets have different structures from the elemental metal.. 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.
Probability-cloud teaching model

4f xyz orbital

One-electron teaching approximation; dots represent sampled probability density, not individual electrons.
Interpretation

What this model does—and does not—show

The displayed 4f_xyz orbital is one representative real f cubic harmonic. It is not a picture of the whole 4f subshell or the electronic bands in the bulk material.

Important: The cloud includes the expected nodal pattern for the named nonrelativistic orbital where applicable. Phase colors are not electric charge. For heavy and superheavy elements, relativistic/many-electron effects make these only teaching approximations.
Real-world archive

Where do I meet holmium?

Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.

One
Laser materials

Laser materials

Ho³⁺-doped crystals such as Ho:YAG support infrared laser transitions; the host crystal is part of the device.

1878Marc Delafontaine and Louis Soret observed spectral evidence for holmium; Per Teodor Cleve independently separated holmium-containing material.
NameHolmium is named from Holmia, the Latin name for Stockholm.
Late 19th centuryFurther rare-earth separation clarified holmium from neighboring erbium and dysprosium.
TodayHolmium remains a specialized magnetic, optical and neutron-absorbing element.
Evidence principleAtomic identity and reference values are source-reviewed. Material viewers are teaching representations, not crystallographic refinements. Search demand shapes headings and FAQs but never overrides measured/evaluated evidence or element-versus-compound distinctions.
Signature science

4f¹¹ → Ho³⁺ → magnetic and infrared optical behavior

Holmium’s signature optical applications use Ho³⁺ inside host crystals; its elemental HCP metal is a separate material.

Evaluated

4f¹¹6s²

Late-lanthanide open 4f shell.

Reference properties

Holmium 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.

PropertyValueContext / provenanceEvidence
Atomic number67Source-reviewed; see Sources belowEvaluated
Relative atomic mass164.930Source-reviewed; see Sources belowEvaluated
Ground-state electron configuration[Xe] 4f¹¹ 6s²Source-reviewed; see Sources belowEvaluated
Group / period / blockGroup Lanthanide · Period 6 · f-blockPeriodic-table placementEvaluated
Electronegativity1.23Source-reviewed; see Sources belowEvaluated
Reference isotope¹⁶⁵HoSource-reviewed; see Sources belowEvaluated
PropertyValueContext / provenanceEvidence
State contextBright silvery lanthanide metalSource-reviewed; see Sources belowEvaluated
Density8.80 g/cm³Source-reviewed; see Sources belowEvaluated
Material / molecular structureHexagonal close-packed (HCP)Ordinary holmium metal is HCP. Optical laser hosts and holmium-containing magnets have different structures from the elemental metal.Measured
ClassificationLanthanidePeriodic-table / chemistry classificationEvaluated
Structure-model scopeOrdinary holmium metal is HCP. Optical laser hosts and holmium-containing magnets have different structures from the elemental metal.Teaching visualization; exact crystallographic coordinates are not implied unless stated.Reviewed
PropertyValueContext / provenanceEvidence
Melting / transition reference1745 KSource-reviewed; see Sources belowEvaluated
Boiling / gas reference2973 KSource-reviewed; see Sources belowEvaluated
Phase-path contextAt approximately standard pressure, holmium is treated as a solid below 1745 K, liquid between melting and approximately 2973 K, and gas above the boiling reference. The ordinary crystal label applies to the stated material reference; unmodeled solid allotropy is not fabricated.Shared phase registry drives the slider, regions and markers.Evaluated
Condition warningTemperature and pressure define phase behavior; purity/allotropy may matter.Teaching condition statementReviewed
PropertyValueContext / provenanceEvidence
Common oxidation states+3Source-reviewed; see Sources belowEvaluated
Ion / common ion contextHo³⁺Source-reviewed; see Sources belowEvaluated
Periodic chemistry contextHolmium is a late lanthanide with [Xe]4f¹¹6s² ground state and dominant Ho³⁺ chemistry. Its partially filled 4f shell gives a very large atomic magnetic moment.Element-specific interpretationReviewed
Chemistry cautionElemental form, ions and compounds are distinct chemical objects.Interpretive teaching ruleReviewed
PropertyValueContext / provenanceEvidence
¹⁶⁵HoNatural isotopeEssentially all natural holmium is ¹⁶⁵Ho.Evaluated
RadioisotopesArtificial isotopesUsed in research and isotope-specific applications.Evaluated
Natural holmiumSingle-isotope natural elementRelative atomic mass is close to the ¹⁶⁵Ho isotope mass.Evaluated
Teaching nucleus¹⁶⁵Ho · 67 protons + 98 neutronsReference isotope used in the nucleus modelReviewed
PropertyValueContext / provenanceEvidence
Page evidence noteAtomic identity and reference values are source-reviewed. Material viewers are teaching representations, not crystallographic refinements. Search demand shapes headings and FAQs but never overrides measured/evaluated evidence or element-versus-compound distinctions.Evidence summary for this guideReviewed
Structure evidenceOrdinary holmium metal is HCP. Optical laser hosts and holmium-containing magnets have different structures from the elemental metal.Measured structure, labelled schematic, prediction or explicit unknown as applicable.Reviewed
Map evidence ruleReal pins are reviewed examples; conceptual layers are used when pins would mislead.Geography Explorer 2.0Reviewed
Source set3 primary/reference links listed belowOpen the Sources section for the actual references.Reviewed
Temperature explorer

Is Holmium a solid, liquid or gas? State at temperature

At approximately standard pressure, holmium is treated as a solid below 1745 K, liquid between melting and approximately 2973 K, and gas above the boiling reference. The ordinary crystal label applies to the stated material reference; unmodeled solid allotropy is not fabricated.

Temperature293 K
Move the slider
The shared site-wide phase model controls the track, markers and readout.
Geography and evidence

Where on Earth is Holmium found or produced?

World map
Geneva, SwitzerlandRSC historical context · historical
Discovery and history

Who discovered Holmium, and when?

1878

Marc Delafontaine and Louis Soret observed spectral evidence for holmium; Per Teodor Cleve independently separated holmium-containing material.

Name

Holmium is named from Holmia, the Latin name for Stockholm.

Late 19th century

Further rare-earth separation clarified holmium from neighboring erbium and dysprosium.

Today

Holmium remains a specialized magnetic, optical and neutron-absorbing element.

Process / synthesis context

From source material to Holmium applications: high-level material path

1

Holmium is obtained from mineral or metallurgical feedstocks in which it is chemically associated with other elements rather than mined as abundant native metal.

2

Industrial separation and refining produce element-specific compounds or metal feedstock; this guide does not provide operational extraction recipes.

3

The refined material is converted into the particular alloy, compound, doped host or component required by the application.

4

Recycling and recovery depend on the host product, concentration and economics; application materials must not be confused with pure element.

Safety boundary: This page is educational. Chemical, occupational, radiological or medical safety decisions require the specific material/isotope, its current safety data and qualified guidance.
Real-world applications

What is holmium used for?

Infrared lasers

Ho-doped host crystals support useful near-2 μm laser transitions.

Magnetic research

Holmium’s large magnetic moment makes it valuable in specialized magnetic materials and experiments.

Neutron absorbers

Holmium-containing materials can be used where neutron capture is useful.

Spectral standards

Sharp Ho absorption features support wavelength calibration in some optical contexts.

Isotopes

Holmium isotopes and natural abundance

¹⁶⁵Ho

Natural isotope

Essentially all natural holmium is ¹⁶⁵Ho.

Radioisotopes

Artificial isotopes

Used in research and isotope-specific applications.

Natural holmium

Single-isotope natural element

Relative atomic mass is close to the ¹⁶⁵Ho isotope mass.

Learn it, don’t just read it

Five-question Holmium check

What is Holmium’s atomic number?

Which classification best fits Holmium?

What is the representative teaching isotope?

Which statement respects the material evidence?

Which rule should guide real-world uses?

Questions answered

Holmium 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 holmium?

Short answer: Holmium is chemical element 67, symbol Ho, a bright silvery lanthanide metal.

Atomic number 67 means every holmium nucleus contains 67 protons. In the periodic table, Holmium is classified here as a lanthanide in Period 6 and Group Lanthanide. Holmium is a late lanthanide with [Xe]4f¹¹6s² ground state and dominant Ho³⁺ chemistry. Its partially filled 4f shell gives a very large atomic magnetic moment.

Key point: Ho is element 67; its periodic position and electron structure explain the rest of the page.

What is holmium used for?

Short answer: Uses include Ho-doped lasers, specialized magnetic materials, neutron absorbers and optical calibration.

Infrared lasers: Ho-doped host crystals support useful near-2 μm laser transitions. Magnetic research: Holmium’s large magnetic moment makes it valuable in specialized magnetic materials and experiments. Holmium can be strongly magnetic, but a “holmium laser” uses Ho ions doped into a host crystal; the laser medium is not a bar of elemental Ho. Nuclear and optical applications are likewise material- or isotope-specific.

Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.

Who discovered holmium?

Short answer: Holmium was identified in 1878 through work by Marc Delafontaine and Louis Soret and independently by Per Teodor Cleve.

In 1878, Marc Delafontaine and Louis Soret observed spectral evidence for holmium; Per Teodor Cleve independently separated holmium-containing material. Holmium is named from Holmia, the Latin name for Stockholm.

Key point: Discovery credit follows the historical evidence and accepted attribution, not just the earliest claim.

Where is holmium found?

Short answer: It occurs as a minor component of rare-earth minerals such as monazite and bastnäsite and is separated with other lanthanides.

Holmium is obtained from mineral or metallurgical feedstocks in which it is chemically associated with other elements rather than mined as abundant native metal. Neutron absorbers Holmium-containing materials can be used where neutron capture is useful.

Key point: Natural occurrence, resources, production and recycling are different geography questions.

Is holmium a metal?

Short answer: Yes. It is a lanthanide metal.

This guide classifies Holmium as a lanthanide. Its periodic position is Period 6, f-block, Group Lanthanide. Holmium is a late lanthanide with [Xe]4f¹¹6s² ground state and dominant Ho³⁺ chemistry. Its partially filled 4f shell gives a very large atomic magnetic moment.

Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.

Is holmium magnetic?

Short answer: Yes. Ho atoms/ions have very large magnetic moments, but bulk magnetic behavior depends on temperature and material context.

Holmium is element 67, a lanthanide with one of the largest atomic magnetic moments. Its Ho³⁺ chemistry connects the periodic table to specialized magnets, neutron absorption and infrared laser materials. Holmium is a late lanthanide with [Xe]4f¹¹6s² ground state and dominant Ho³⁺ chemistry. Its partially filled 4f shell gives a very large atomic magnetic moment.

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 does holmium look like?

Short answer: Elemental holmium is a bright silvery metal.

The ordinary elemental-material description used here is: Bright silvery lanthanide metal. Holmium can be strongly magnetic, but a “holmium laser” uses Ho ions doped into a host crystal; the laser medium is not a bar of elemental Ho. Nuclear and optical applications are likewise material- or isotope-specific.

Key point: Elemental appearance can differ from the colors of its ions, compounds, oxide films or host materials.

Is holmium toxic?

Short answer: Holmium has no known biological role; safety should be based on the specific chemical form and applicable material data.

This page is educational. Chemical, occupational, radiological or medical safety decisions require the specific material/isotope, its current safety data and qualified guidance.

Key point: Safety claims must be substance- and exposure-specific.

Scientific sources and provenance

Scientific sources for Holmium

Evidence rule: Atomic identity and reference values are source-reviewed. Material viewers are teaching representations, not crystallographic refinements. Search demand shapes headings and FAQs but never overrides measured/evaluated evidence or element-versus-compound distinctions.
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