Element identity / phase data
Atomic number, electron configuration, density and phase references are evaluated data.
BCC metal view
The ordinary metallic structure is represented with a simplified conventional BCC cell.
BaSO4 distinction
Insoluble barium sulfate is distinguished from reactive metal and soluble barium compounds.
Commodity geography
Selected barite regions are dated/illustrative, not a complete occurrence map.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Barium (Ba)
Barium is element 56, a reactive Group 2 metal whose chemistry is encountered far more often in compounds than as exposed metal. Its story connects 6s² electrons, Ba²⁺ chemistry, barite resources, green emission and the special insolubility of barium sulfate.
Barium atomic number, mass, electron configuration and key properties
Barium has 56 protons. A neutral barium atom has 56 electrons; barium-138 has 82 neutrons. Barium belongs to Group 2, the alkaline-earth metals.
Barium: quick answers
How many protons, neutrons and electrons does barium have?
Barium’s atomic number is 56, so every barium atom has 56 protons, and a neutral atom also has 56 electrons. Its most common natural isotope, barium-138, has 82 neutrons (other isotopes have different neutron counts).
What is the symbol for barium?
The chemical symbol for barium is Ba.
Is barium a solid, liquid or gas at room temperature?
Barium is a solid at room temperature (about 25 °C).
What family (group) is barium in?
Barium is an alkaline earth metal, in group 2, period 6 of the periodic table.
How many valence electrons does barium have?
Barium has 2 valence electrons, the electrons in its outer shell, which matches its position in group 2.
What is the electron configuration of barium?
The ground-state electron configuration of barium is [Xe] 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.
56 protons define barium.
The reference ground-state configuration frames atomic and chemical behavior.
Periodic position organizes recurring trends without replacing element-specific evidence.
The teaching nucleus is one isotope, not the relative atomic mass.
Phase claims are evidence-labelled; unknown superheavy bulk boundaries are not fabricated.
Barium in its period and family
Barium is the Period 6 member of Group 2, below strontium. Its two outer 6s electrons support common +2 chemistry and strong electropositivity.
Barium Visual Lab
Compare Ba with Ba²⁺, rotate a ¹³⁸Ba teaching nucleus and BCC metal cell, inspect the 6s probability model, then connect atomic structure to barite, drilling fluids, green emission and barium-sulfate contrast media.
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.
Barium in one minute
Atomic number 56 means every barium nucleus has 56 protons.
Neutral barium has the ground-state configuration [Xe] 6s².
Barium commonly forms Ba²⁺ compounds.
Elemental barium is reactive; it is not the same material as barite or barium sulfate.
BaSO₄ is exceptionally insoluble, which is central to its contrast-imaging use.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 18 · 8 · 2 electrons
The occupied 6s orbital is shown as a spherical probability distribution in a hydrogen-like teaching approximation. It is not an electron orbit or a metallic band calculation.
Barium is represented with a body-centred-cubic teaching cell for the ordinary metallic phase. The model is a conventional cell, not a full diffraction refinement.. 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 6s orbital is shown as a spherical probability distribution in a hydrogen-like teaching approximation. It is not an electron orbit or a metallic band calculation.
Where do I meet barium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Barite and drilling
Most commercial barium demand is tied to barite (BaSO₄), especially as a high-density drilling-fluid additive.
Ba metal → Ba2+ → BaSO4: chemical form changes the story
“Barium” is not one material. The atom, common ion and highly insoluble sulfate have different properties and safety contexts.
Reactive Group 2 metal
Elemental barium is a soft reactive metal with a 6s2 outer configuration.
Calcium, strontium and barium
Follow the recurring ns2 pattern down Group 2 while size, density and reactivity change.
| Outer shell | 4s² |
|---|---|
| Atomic no. | 20 |
| Outer shell | 5s² |
|---|---|
| Atomic no. | 38 |
| Outer shell | 6s² |
|---|---|
| Atomic no. | 56 |
Barium 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 | 56 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 137.327 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Xe] 6s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 2 · Period 6 · s-block | Periodic-table placement | Evaluated |
| Electronegativity | 0.89 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ¹³⁸Ba | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Soft silvery solid at 20 °C | Source-reviewed; see Sources below | Evaluated |
| Density | 3.62 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Barium metal · body-centred cubic | Barium is represented with a body-centred-cubic teaching cell for the ordinary metallic phase. The model is a conventional cell, not a full diffraction refinement. | Measured |
| Classification | Alkaline earth metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Barium is represented with a body-centred-cubic teaching cell for the ordinary metallic phase. The model is a conventional cell, not a full diffraction refinement. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 1000 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 2118 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, barium is a BCC solid below about 1000 K, liquid to about 2118 K, and gaseous above the boiling reference. | 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 | Ba²⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Barium is the Period 6 member of Group 2, below strontium. Its two outer 6s electrons support common +2 chemistry and strong electropositivity. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ¹³⁸Ba | Stable · most abundant natural isotope | Reference teaching nucleus with 56 protons and 82 neutrons. | Evaluated |
| ¹³⁷Ba | Stable natural isotope | One of several stable natural barium isotopes. | Evaluated |
| ¹³³Ba | Radioactive tracer/calibration isotope | Used in controlled research/metrology contexts; distinct from stable bulk barium. | Evaluated |
| Teaching nucleus | ¹³⁸Ba · 56 protons + 82 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Barium a solid, liquid or gas? State at temperature
At approximately standard pressure, barium is a BCC solid below about 1000 K, liquid to about 2118 K, and gaseous above the boiling reference.
Where on Earth is Barium found or produced?
Who discovered Barium, and when?
Carl Wilhelm Scheele distinguished a new “heavy spar” earth in barite-related material.
Humphry Davy isolated barium by electrolysis, establishing the metal as an element.
Barite became an important industrial mineral, particularly as a dense drilling-fluid material.
Barium chemistry spans industrial minerals, glass/ceramics, spectroscopy and medically supervised BaSO₄ contrast.
From barite to barium products: a high-level supply path
Barium occurs mainly in minerals such as barite (BaSO₄), not as native metal.
Mining and beneficiation concentrate barite for industrial markets.
Chemical processing can convert selected feedstocks into barium compounds; this page does not provide preparation procedures.
Applications depend strongly on chemical form, from dense barite to specialty salts, ceramics and highly insoluble BaSO₄ contrast media.
What is barium used for?
Drilling fluids
Ground barite is widely used to increase drilling-fluid density.
Medical imaging
BaSO₄ suspensions provide gastrointestinal contrast because the compound is highly insoluble and X-ray attenuating.
Glass & ceramics
Barium compounds modify selected optical, ceramic and electronic materials.
Spectroscopy & colour
Barium emission provides a distinctive green spectral/flame signature.
Barium isotopes and natural abundance
¹³⁸Ba
Stable · most abundant natural isotopeReference teaching nucleus with 56 protons and 82 neutrons.
¹³⁷Ba
Stable natural isotopeOne of several stable natural barium isotopes.
¹³³Ba
Radioactive tracer/calibration isotopeUsed in controlled research/metrology contexts; distinct from stable bulk barium.
Five-question Barium check
What is barium’s atomic number?
What is the common barium ion?
Which compound is central to barite and medical contrast?
What is the ordinary metal teaching structure?
Why should “barium” not be treated as one safety category?
Barium 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.
How many protons does barium have?
Short answer: Barium has 56 protons, because its atomic number is 56.
Atomic number counts protons, so every barium isotope has 56 protons. A neutral barium atom has 56 electrons, but neutron counts differ by isotope: barium-138 has 138 − 56 = 82 neutrons. Barium is a Group 2 alkaline-earth metal; the common Ba²⁺ ion has two fewer electrons than neutral Ba.
Key point: 56 protons define barium; the isotope fixes the neutron count, and ion charge changes the electron count.
Is barium a metal?
Short answer: Yes. Elemental barium is a reactive Group 2 alkaline-earth metal.
This guide classifies Barium as an alkaline earth metal. Its periodic position is Period 6, s-block, Group 2. Barium is the Period 6 member of Group 2, below strontium. Its two outer 6s electrons support common +2 chemistry and strong electropositivity.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
What is barium used for?
Short answer: Most commercial barium is used as compounds, especially barite in drilling fluids; BaSO₄ also has medical contrast uses.
Drilling fluids: Ground barite is widely used to increase drilling-fluid density. Medical imaging: BaSO₄ suspensions provide gastrointestinal contrast because the compound is highly insoluble and X-ray attenuating. “Barium” can mean the element, Ba²⁺ in compounds, barite (BaSO₄), or a medical barium-sulfate suspension. Those are not interchangeable: chemical form and solubility matter.
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 barium have?
Short answer: Two in the neutral atom, from the 6s² outer configuration.
The neutral-atom ground-state reference used on this page is [Xe] 6s². 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.
Is barium radioactive?
Short answer: Natural barium is mostly stable isotopes. Some radioactive barium isotopes exist, but radioactivity is not a defining property of ordinary natural barium.
¹³⁸Ba: Stable · most abundant natural isotope: Reference teaching nucleus with 56 protons and 82 neutrons. ¹³⁷Ba: Stable natural isotope: One of several stable natural barium isotopes.
Key point: Radioactivity is isotope-specific; do not apply one isotope’s nuclear behavior to every atom of the element.
Why can barium sulfate be used medically if barium chemistry can be hazardous?
Short answer: BaSO₄ is extremely insoluble, so its behavior differs fundamentally from soluble barium salts and reactive elemental barium.
Elemental barium is reactive and many soluble barium compounds can be hazardous. Medical BaSO₄ use occurs under professional control and is not a general statement that all barium compounds are safe.
Key point: Safety claims must be substance- and exposure-specific.
Scientific sources for Barium
- Royal Society of Chemistry - Barium
- NIST - Atomic Data for Barium
- USGS - Mineral Commodity Summaries 2026
Questions to ask next about Barium
A good element lesson should lead to the next useful question, not end after a list of facts.
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