Barium Atomic Number

Barium is a naturally occurring alkaline metalloid element with atomic symbol Ba, atomic number 56, and atomic weight 137 that is only found in combination with other elements, typically barite (barium sulfate) and witherite (barium carbonate), or chemicals. There are seven naturally occurring isotopes of barium: barium-130, barium-132, barium-134, barium-135, barium-136, barium-137, and barium-138. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number.

Element Barium – Ba

Comprehensive data on the chemical element Barium is provided on this page; including scores of properties, element names in many languages, most known nuclides of Barium. Common chemical compounds are also provided for many elements. In addition technical terms are linked to their definitions and the menu contains links to related articles that are a great aid in one”s studies.

Barium Menu

  • Barium Page One
  • Barium Page Two
  • Barium Page Three

Overview of Barium

  • Atomic Number: 56
  • Group: 2
  • Period: 6
  • Series: Alkali Earth Metals

Barium”s Name in Other Languages

  • Latin: Baryum
  • Czech: Baryum
  • Croatian: Barij
  • French: Baryum
  • German: Barium – s
  • Italian: Bario
  • Norwegian: Barium
  • Portuguese: Bário
  • Russian: Барий
  • Spanish: Bario
  • Swedish: Barium

Atomic Structure of Barium

  • Atomic Radius: 2.78Å
  • Atomic Volume: 39.24cm3/mol
  • Covalent Radius: 1.98Å
  • Cross Section (Thermal Neutron Capture)σa/barns: 1.3
  • Crystal Structure: Cubic body centered
  • Electron Configuration:
    1s2 2s2p6 3s2p6d10 4s2p6d10 5s2p6 6s2
  • Electrons per Energy Level: 2,8,18,18,8,2
    Shell Model
  • Ionic Radius: 1.35Å
  • Filling Orbital: 6s2
  • Number of Electrons (with no charge): 56
  • Number of Neutrons (most common/stable nuclide): 81
  • Number of Protons: 56
  • Oxidation States: 2
  • Valence Electrons: 6s2
    Electron Dot Model

Chemical Properties of Barium

  • Electrochemical Equivalent: 2.5621g/amp-hr
  • Electron Work Function: 2.7eV
  • Electronegativity: 0.89 (Pauling); 0.97 (Allrod Rochow)
  • Heat of Fusion: 7.75kJ/mol
  • Incompatibilities:
  • Ionization Potential
    • First: 5.212
    • Second: 10.004
  • Valence Electron Potential (-eV): 21.3

Physical Properties of Barium

  • Atomic Mass Average: 137.327
  • Boiling Point: 2171K 1898°C 3448°F
  • Coefficient of lineal thermal expansion/K-1: 18.1E-6
  • Conductivity
    Electrical: 0.03 106/cm Ω
    Thermal: 0.184 W/cmK
  • Density: 3.59g/cc @ 300K
  • Description:
    Soft heavy silver colored metal.
  • Elastic Modulus:
    • Bulk: 9.6/GPa
    • Rigidity: 4.86/GPa
    • Youngs: 12.8/GPa
  • Enthalpy of Atomization: 175.7 kJ/mole @ 25°C
  • Enthalpy of Fusion: 7.66 kJ/mole
  • Enthalpy of Vaporization: 140 kJ/mole
  • Flammablity Class:
  • Freezing Point:see melting point
  • Hardness Scale
    • Mohs: 1.25
  • Heat of Vaporization: 142kJ/mol
  • Melting Point: 1002K 729°C 1344°F
  • Molar Volume: 38.21 cm3/mole
  • Physical State (at 20°C & 1atm): Solid
  • Specific Heat: 0.204J/gK
  • Vapor Pressure = [email protected]°C

Regulatory / Health

  • CAS Number
    • 7440-39-3
  • RTECS: CQ8370000
  • NFPA 704
    • Health: 2
    • Fire: 2
    • Reactivity:
    • Special Hazard:
  • OSHAPermissible Exposure Limit (PEL)
    • No limits set by OSHA
  • OSHA PEL Vacated 1989
    • No limits set by OSHA
  • NIOSHRecommended Exposure Limit (REL)
    • No limits set by NIOSH
  • Levels In Humans:
    Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
    • Blood/mg dm-3: 0.068
    • Bone/p.p.m: 3-70
    • Liver/p.p.m: 0.04-1.2
    • Muscle/p.p.m: 0.09
    • Daily Dietary Intake: 0.6-1.7 mg
    • Total Mass In Avg. 70kg human: 22 mg

Barium Atomic Number And Mass

Who / Where / When / How

  • Discoverer: Sir Humphrey Davy
  • Discovery Location: London England
  • Discovery Year: 1808
  • Name Origin:
    Greek: barys (heavy or dense).
  • Abundance of Barium:
    • Earth”s Crust/p.p.m.: 500
    • Seawater/p.p.m.:
      • Atlantic Suface: 0.0047
      • Atlantic Deep: 0.0093
      • Pacific Surface: 0.0047
      • Pacific Deep: 0.02
    • Atmosphere/p.p.m.: N/A
    • Sun (Relative to H=1E12): 123
  • Sources of Barium:
    Found in barytine (BaSO4) and witherite (BaCO3),never found in pure form due to its reactivity. Total annual world production estimated around 6,000,000 tons. Main mining areas are UK, Italy, Czech Republic, USA and Germany. Total world reserves estimated to be around 450,000,000 tons.
  • Uses of Barium:
    Used in sparkplugs, vacuum tubes, fireworks, fluorescent lamps. Insoluble barium sulfate is used for body imaging.
  • Additional Notes:
    Must be stored under kerosene to remain pure. Soluble barium salts are highly toxic.

Barium Menu

  • Barium Page One
  • Barium Page Two
  • Barium Page Three


A list of reference sources used to compile the data provided on our periodic table of elements can be found on the main periodic table page. Tayasui sketches pro apk.

Related Resources

  • Anatomy of the Atom
    Answers many questions regarding the structure of atoms.
  • Molarity, Molality and Normality
    Introduces stoichiometry and explains the differences between molarity, molality and normality.
  • Molar Mass Calculations and Javascript Calculator
    Molar mass calculations are explained and there is a JavaScript calculator to aid calculations.
  • Chemical Database
    This database focuses on the most common chemical compounds used in the home and industry.

Citing this page

If you need to cite this page, you can copy this text:

Kenneth Barbalace. Periodic Table of Elements – Barium – Ba. 1995 – 2021. Accessed on-line: 4/24/2021

Linking to this page

Barium Ka Atomic Number

If you would like to link to this page from your website, blog, etc., copy and paste this link code (in red) and modify it to suit your needs:

Barium Electron Configuration

<a href=””>echo Periodic Table of Elements: Barium – Ba (</a>- Comprehensive information for the element Barium – Ba is provided by this page including scores of properties, element names in many languages, most known nuclides and technical terms are linked to their definitions.



Barium Atomic Number And Symbol

PLEASE, if you like an article we published simply link to it on our website do not republish it.