Atomic / phase data
Reference atomic and phase values are source-reviewed.
Material structure
The ordinary elemental structure is measured/reviewed; the viewer is a teaching representation.
Element vs material uses
Uses distinguish elemental metal from compounds, alloys, doped hosts or isotope-specific systems.
Geography
Discovery/supply context is selective and does not fabricate deposits, facilities or inventories.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Erbium (Er)
Erbium is element 68, a lanthanide whose Er³⁺ optical transitions connect the periodic table to fiber-optic amplifiers, lasers, pink glass and specialized photonic materials.
Erbium atomic number, mass, electron configuration and key properties
Erbium: quick answers
How many protons, neutrons and electrons does erbium have?
Erbium’s atomic number is 68, so every erbium atom has 68 protons, and a neutral atom also has 68 electrons. Its most common natural isotope, erbium-166, has 98 neutrons (other isotopes have different neutron counts).
What is the symbol for erbium?
The chemical symbol for erbium is Er.
Is erbium a solid, liquid or gas at room temperature?
Erbium is a solid at room temperature (about 25 °C).
What family (group) is erbium in?
Erbium 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 erbium?
The ground-state electron configuration of erbium is [Xe] 4f¹² 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.
68 protons define erbium.
The ground-state configuration frames atomic and chemical behavior.
Periodic position organizes recurring chemistry and trends.
The teaching nucleus is one isotope, not the relative atomic mass.
Phase claims preserve source-reviewed evidence and material context.
Erbium in its period and family
Erbium is a late Period 6 lanthanide. Its [Xe]4f¹²6s² atom most commonly forms Er³⁺, whose 4f transitions are especially important in near-infrared optics.
Erbium Visual Lab
Explore Er 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.
Erbium in one minute
Atomic number 68 means every erbium nucleus has 68 protons.
Neutral Erbium has the ground-state configuration [Xe] 4f¹² 6s².
The representative teaching isotope is ¹⁶⁶Er.
The famous telecom role belongs to Er³⁺ ions doped into glass fibers, not to metallic erbium wires.
The ordinary material reference is Hexagonal close-packed (HCP).
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 30 · 8 · 2 electrons
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.
Ordinary erbium metal is HCP. Pink Er₂O₃ and Er-doped glasses or fibers are separate compound/host materials and are not represented by this metal lattice.. 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 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.
Where do I meet erbium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Fiber amplifiers
Er³⁺-doped silica fibers can amplify light near the low-loss telecom window around 1.55 μm.
4f¹² → Er³⁺ → 1.55 μm photonics
Erbium’s telecom signature belongs to Er³⁺ ions inside a glass host. The host composition and ion state are essential to the optical function.
4f¹²6s²
Late-lanthanide open 4f shell.
Erbium in periodic context
Compare nearby or family-related elements without treating a trend as a substitute for element-specific evidence.
| Atomic number | 67 |
|---|---|
| Series | lanthanide |
| Atomic number | 68 |
|---|---|
| Series | lanthanide |
| Atomic number | 69 |
|---|---|
| Series | lanthanide |
Erbium 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 | 68 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 167.259 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 4f¹² 6s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group Lanthanide · Period 6 · f-block | Periodic-table placement | Evaluated |
| Electronegativity | 1.24 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ¹⁶⁶Er | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Soft silvery lanthanide metal | Source-reviewed; see Sources below | Evaluated |
| Density | 9.07 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Hexagonal close-packed (HCP) | Ordinary erbium metal is HCP. Pink Er₂O₃ and Er-doped glasses or fibers are separate compound/host materials and are not represented by this metal lattice. | Measured |
| Classification | Lanthanide | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Ordinary erbium metal is HCP. Pink Er₂O₃ and Er-doped glasses or fibers are separate compound/host materials and are not represented by this metal lattice. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 1802 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 3141 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, erbium is treated as a solid below 1802 K, liquid between melting and approximately 3141 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 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 | Er³⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Erbium is a late Period 6 lanthanide. Its [Xe]4f¹²6s² atom most commonly forms Er³⁺, whose 4f transitions are especially important in near-infrared optics. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ¹⁶⁶Er | Most abundant natural isotope | Reference teaching isotope for this page. | Evaluated |
| Natural erbium | Multiple-isotope element | Several naturally occurring isotopes contribute to the atomic weight. | Evaluated |
| Radioisotopes | Artificial isotopes | Used mainly in research and isotope-specific applications. | Evaluated |
| Teaching nucleus | ¹⁶⁶Er · 68 protons + 98 neutrons | Reference isotope used in the nucleus model | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Page evidence note | 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. | Evidence summary for this guide | Reviewed |
| Structure evidence | Ordinary erbium metal is HCP. Pink Er₂O₃ and Er-doped glasses or fibers are separate compound/host materials and are not represented by this metal lattice. | 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 Erbium a solid, liquid or gas? State at temperature
At approximately standard pressure, erbium is treated as a solid below 1802 K, liquid between melting and approximately 3141 K, and gas above the boiling reference. The ordinary crystal label applies to the stated material reference; unmodeled solid allotropy is not fabricated.
Where on Earth is Erbium found or produced?
Who discovered Erbium, and when?
Carl Gustaf Mosander separated an erbium-containing oxide while studying yttria-derived rare-earth fractions.
Historical naming of erbia/terbia shifted as rare-earth separations were corrected.
High-purity Er compounds enabled optical spectroscopy and laser development.
Erbium-doped fiber amplifiers became central to long-distance optical communications.
From source material to Erbium applications: high-level material path
Erbium is obtained from mineral or metallurgical feedstocks in which it is chemically associated with other elements rather than mined as abundant native metal.
Industrial separation and refining produce element-specific compounds or metal feedstock; this guide does not provide operational extraction recipes.
The refined material is converted into the particular alloy, compound, doped host or component required by the application.
Recycling and recovery depend on the host product, concentration and economics; application materials must not be confused with pure element.
What is erbium used for?
Fiber-optic amplifiers
Er³⁺ in silica can amplify optical signals around telecommunications wavelengths.
Lasers
Er-doped crystals and glasses are used in specialized laser systems.
Glass & ceramics
Er compounds provide pink coloration and optical absorption features.
Metallurgy
Er additions are used in selected alloy and materials research contexts.
Erbium isotopes and natural abundance
¹⁶⁶Er
Most abundant natural isotopeReference teaching isotope for this page.
Natural erbium
Multiple-isotope elementSeveral naturally occurring isotopes contribute to the atomic weight.
Radioisotopes
Artificial isotopesUsed mainly in research and isotope-specific applications.
Five-question Erbium check
What is Erbium’s atomic number?
Which classification best fits Erbium?
What is the representative teaching isotope?
Which statement respects the material evidence?
Which rule should guide real-world uses?
Erbium 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 erbium?
Short answer: Erbium is chemical element 68, symbol Er, a soft silvery lanthanide metal.
Atomic number 68 means every erbium nucleus contains 68 protons. In the periodic table, Erbium is classified here as a lanthanide in Period 6 and Group Lanthanide. Erbium is a late Period 6 lanthanide. Its [Xe]4f¹²6s² atom most commonly forms Er³⁺, whose 4f transitions are especially important in near-infrared optics.
Key point: Er is element 68; its periodic position and electron structure explain the rest of the page.
What is erbium used for?
Short answer: Major uses include erbium-doped fiber amplifiers, lasers and colored/optical glasses.
Fiber-optic amplifiers: Er³⁺ in silica can amplify optical signals around telecommunications wavelengths. Lasers: Er-doped crystals and glasses are used in specialized laser systems. The famous telecom role belongs to Er³⁺ ions doped into glass fibers, not to metallic erbium wires. Er metal, Er₂O₃ and Er-doped silica are different materials with different structures and functions.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Where is erbium found?
Short answer: It occurs mixed with other rare earths in minerals such as monazite and bastnäsite and is separated during rare-earth processing.
Erbium is obtained from mineral or metallurgical feedstocks in which it is chemically associated with other elements rather than mined as abundant native metal. 1843 Carl Gustaf Mosander separated an erbium-containing oxide while studying yttria-derived rare-earth fractions.
Key point: Natural occurrence, resources, production and recycling are different geography questions.
Who discovered erbium?
Short answer: Carl Gustaf Mosander identified erbium in 1843 during rare-earth separation work.
In 1843, Carl Gustaf Mosander separated an erbium-containing oxide while studying yttria-derived rare-earth fractions. In the 19th century, Historical naming of erbia/terbia shifted as rare-earth separations were corrected.
Key point: Discovery credit follows the historical evidence and accepted attribution, not just the earliest claim.
Is erbium a metal?
Short answer: Yes. It is a lanthanide metal.
This guide classifies Erbium as a lanthanide. Its periodic position is Period 6, f-block, Group Lanthanide. Erbium is a late Period 6 lanthanide. Its [Xe]4f¹²6s² atom most commonly forms Er³⁺, whose 4f transitions are especially important in near-infrared optics.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
Why is erbium used in fiber optics?
Short answer: Er³⁺ ions have optical transitions near 1.55 μm, a key low-loss telecommunications window in silica fiber.
Erbium is a late Period 6 lanthanide. Its [Xe]4f¹²6s² atom most commonly forms Er³⁺, whose 4f transitions are especially important in near-infrared optics. Erbium is element 68, a lanthanide whose Er³⁺ optical transitions connect the periodic table to fiber-optic amplifiers, lasers, pink glass and specialized photonic materials.
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 color is erbium?
Short answer: The elemental metal is silvery; Er³⁺ compounds can produce pink coloration in glass and ceramics.
The ordinary elemental-material description used here is: Soft silvery lanthanide metal. Glass & ceramics Er compounds provide pink coloration and optical absorption features.
Key point: Elemental appearance can differ from the colors of its ions, compounds, oxide films or host materials.
How many electrons does erbium have?
Short answer: A neutral erbium atom has 68 electrons with ground-state configuration [Xe] 4f¹² 6s².
A neutral atom has the same number of electrons as protons, so neutral Erbium has 68 electrons. Its ground-state reference configuration is [Xe] 4f¹² 6s²; ions have different electron counts because electrons have been removed or added.
Key point: Electron count changes in ions; proton count does not.
Scientific sources for Erbium
- Royal Society of Chemistry - Erbium
- NIST - Atomic Weights and Isotopic Compositions
- IUPAC - Periodic Table of Elements
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