Atomic / phase data
Reference atomic and ordinary phase values are evaluated.
Crystal structure
HCP is the ordinary-condition metal structure; viewer is schematic.
Health context
Occupational beryllium hazard is explicit; no exposure procedures are given.
Geography
Resource/production examples are source-reviewed and dated.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Beryllium (Be)
Beryllium is element 4, an unusually light and stiff Group 2 metal. Its low atomic number, compact atoms and strong bonding connect atomic structure to X-ray windows, aerospace materials and a strict occupational-health boundary.
Beryllium atomic number, mass, electron configuration and key properties
Beryllium: quick answers
How many protons, neutrons and electrons does beryllium have?
Beryllium’s atomic number is 4, so every beryllium atom has 4 protons, and a neutral atom also has 4 electrons. Its most common natural isotope, beryllium-9, has 5 neutrons (other isotopes have different neutron counts).
What is the symbol for beryllium?
The chemical symbol for beryllium is Be.
Is beryllium a solid, liquid or gas at room temperature?
Beryllium is a solid at room temperature (about 25 °C).
What family (group) is beryllium in?
Beryllium is an alkaline earth metal, in group 2, period 2 of the periodic table.
How many valence electrons does beryllium have?
Beryllium has 2 valence electrons, the electrons in its outer shell, which matches its position in group 2.
What is the electron configuration of beryllium?
The ground-state electron configuration of beryllium is [He] 2s².
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.
4 protons define beryllium.
The ground-state configuration provides the starting point for its chemistry.
Periodic position organizes recurring chemistry and trends.
The teaching nucleus is one isotope, not the relative atomic mass.
Phase boundaries are condition-dependent and evidence-labelled.
Beryllium in its period and family
Beryllium sits in Group 2, Period 2. Its small size makes its chemistry less purely ionic than a simple “alkaline-earth metal” label might suggest.
Beryllium Visual Lab
Decode beryllium’s tile, compare Be with Be²⁺, rotate a ⁹Be teaching nucleus and HCP metal cell, inspect the 2s probability model, then connect structure to X-ray transmission, alloys and resource geology.
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.
Beryllium in one minute
Atomic number 4 means every beryllium nucleus has 4 protons.
Neutral beryllium has the ground-state configuration [He] 2s².
Beryllium commonly forms +2 compounds.
Beryllium is light and exceptionally stiff for its density.
Beryllium dust and fumes require professional exposure controls; useful material properties do not imply harmlessness.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 2 electrons
The occupied 2s orbital is shown as a spherical probability distribution with a radial node in a hydrogen-like teaching approximation; it is not an electron orbit or a bulk band-structure calculation.
Beryllium is hexagonal close-packed at ordinary conditions. The viewer is a conventional-cell teaching schematic, not a crystallographic coordinate file.. 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 occupied 2s orbital is shown as a spherical probability distribution with a radial node in a hydrogen-like teaching approximation; it is not an electron orbit or a bulk band-structure calculation.
Where do I meet beryllium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
X-ray windows
Thin beryllium can transmit X-rays efficiently because of its low atomic number, while remaining mechanically useful.
Low-Z X-ray window + light, stiff metal
Beryllium’s unusually low atomic number and strong metallic bonding produce a rare engineering combination—and a serious exposure boundary.
Low-Z Be atom
Only four protons/electrons means relatively weak X-ray absorption compared with many structural metals.
Beryllium, magnesium and calcium
Compare nearby elements to see which patterns repeat and which properties remain element-specific.
| Atomic no. | 4 |
|---|---|
| Electronegativity | 1.57 |
| Density | 1.85 g/cm³ |
| Atomic no. | 12 |
|---|---|
| Electronegativity | 1.31 |
| Density | 1.74 g/cm³ |
| Atomic no. | 20 |
|---|---|
| Electronegativity | 1.00 |
| Density | 1.55 g/cm³ |
Beryllium 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 | 4 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 9.0122 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [He] 2s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 2 · Period 2 · s-block | Periodic-table placement | Evaluated |
| Electronegativity | 1.57 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ⁹Be | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Light grey solid at 20 °C | Source-reviewed; see Sources below | Evaluated |
| Density | 1.85 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Beryllium metal · hexagonal close-packed | Beryllium is hexagonal close-packed at ordinary conditions. The viewer is a conventional-cell teaching schematic, not a crystallographic coordinate file. | Measured |
| Classification | Alkaline earth metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Beryllium is hexagonal close-packed at ordinary conditions. The viewer is a conventional-cell teaching schematic, not a crystallographic coordinate file. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 1560 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 2741 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, beryllium is solid below about 1560 K, liquid from melting to about 2741 K, and gaseous above the boiling reference. High-pressure polymorphs are outside this teaching track. | 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 | +2 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Be²⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Beryllium sits in Group 2, Period 2. Its small size makes its chemistry less purely ionic than a simple “alkaline-earth metal” label might suggest. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ⁹Be | Stable · essentially all natural beryllium | The reference teaching nucleus contains 4 protons and 5 neutrons. | Evaluated |
| ¹⁰Be | Long-lived cosmogenic radionuclide | Produced naturally by cosmic-ray interactions and used in Earth-science dating/tracing contexts. | Evaluated |
| Beryllium isotope context | One stable natural isotope | Beryllium is effectively monoisotopic in nature, unlike many neighboring elements. | Evaluated |
| Teaching nucleus | ⁹Be · 4 protons + 5 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Beryllium a solid, liquid or gas? State at temperature
At approximately standard pressure, beryllium is solid below about 1560 K, liquid from melting to about 2741 K, and gaseous above the boiling reference. High-pressure polymorphs are outside this teaching track.
Where on Earth is Beryllium found or produced?
Who discovered Beryllium, and when?
Nicolas-Louis Vauquelin recognized a new element in beryl and emerald.
Friedrich Wöhler and Antoine Bussy independently isolated the metal.
Specialized uses developed in aerospace, nuclear, X-ray and high-performance alloy applications.
Beryllium is a strategically important specialty material whose use is paired with strict exposure controls.
From beryllium mineral to engineered material: a high-level path
Beryllium occurs in minerals such as bertrandite and beryl rather than as native metal.
Mining and beneficiation concentrate beryllium-bearing feed; deposit-specific methods are not described here.
Chemical conversion and metal/alloy production are industrial processes requiring controlled facilities and exposure management.
Fabrication creates specialty components, while scrap recovery can return valuable beryllium-bearing material to controlled industrial streams.
What is beryllium used for?
Aerospace & instruments
Low density and stiffness make beryllium useful in selected precision and aerospace structures.
X-ray equipment
Thin beryllium windows transmit X-rays while maintaining a physical barrier.
Copper alloys
Copper-beryllium alloys combine conductivity with high strength in specialized parts.
Scientific systems
Beryllium appears in selected research, detector and optical applications where its unusual material properties matter.
Beryllium isotopes and natural abundance
⁹Be
Stable · essentially all natural berylliumThe reference teaching nucleus contains 4 protons and 5 neutrons.
¹⁰Be
Long-lived cosmogenic radionuclideProduced naturally by cosmic-ray interactions and used in Earth-science dating/tracing contexts.
Beryllium isotope context
One stable natural isotopeBeryllium is effectively monoisotopic in nature, unlike many neighboring elements.
Five-question Beryllium check
What is beryllium’s atomic number?
How many valence electrons does neutral beryllium have?
What room-temperature crystal teaching model is used?
Why is beryllium useful for some X-ray windows?
Which exposure statement is correct?
Beryllium 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 beryllium’s atomic number?
Short answer: 4. Every beryllium nucleus contains four protons.
Atomic number is defined by proton count, so 4 protons are what make an atom beryllium. A neutral beryllium atom also has 4 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
Is beryllium a metal?
Short answer: Yes. Beryllium is a Group 2 alkaline-earth metal, though its small size gives its compounds distinctive bonding behavior.
This guide classifies Beryllium as an alkaline earth metal. Its periodic position is Period 2, s-block, Group 2. Beryllium sits in Group 2, Period 2. Its small size makes its chemistry less purely ionic than a simple “alkaline-earth metal” label might suggest.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
What is beryllium used for?
Short answer: Selected uses include aerospace and precision components, X-ray windows and copper-beryllium alloys.
Aerospace & instruments: Low density and stiffness make beryllium useful in selected precision and aerospace structures. X-ray equipment: Thin beryllium windows transmit X-rays while maintaining a physical barrier. Beryllium combines very low density with high stiffness, but useful properties do not erase hazard: inhalation of beryllium-containing dust or fumes can cause serious disease. This guide separates the bulk metal from exposure pathways.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
How many valence electrons does beryllium have?
Short answer: Two, from the 2s² outer configuration.
The neutral-atom ground-state reference used on this page is [He] 2s². This is an isolated-atom reference: bonding and ion formation can change which outer electrons are present or chemically active. The listed common oxidation-state context is +2, which helps connect the atomic configuration to ordinary chemistry without treating electron counting as a single universal rule.
Key point: Electron configuration is a ground-state atomic reference, not a literal picture of every compound.
Why can beryllium transmit X-rays?
Short answer: Its low atomic number gives relatively weak X-ray absorption compared with many structural metals, allowing thin windows to be useful.
X-ray windows Thin beryllium can transmit X-rays efficiently because of its low atomic number, while remaining mechanically useful. X-ray equipment Thin beryllium windows transmit X-rays while maintaining a physical barrier.
Key point: Use the direct answer together with the material, isotope and evidence context shown elsewhere on the page.
Why is beryllium toxic?
Short answer: Beryllium is a serious occupational inhalation hazard: airborne beryllium-containing dusts or fumes can trigger immune sensitization and chronic beryllium disease in susceptible people, and occupational exposure is also associated with cancer risk.
Toxicity depends on chemical form, particle size, dose and exposure route. The major well-established workplace concern is inhalation of respirable beryllium-containing particles, not a simplistic claim that every intact piece of beryllium creates the same exposure. Safety guidance therefore focuses on controlling airborne exposure and professional industrial hygiene.
Key point: Distinguish the element/material from the biologically available airborne particles that drive the major occupational hazard.
Scientific sources for Beryllium
- Royal Society of Chemistry - Beryllium
- NIST - Atomic Data for Beryllium
- USGS - Mineral Commodity Summaries 2026
- CDC/NIOSH — Beryllium
Questions to ask next about Beryllium
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.