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Periodic Table of Elements

Element Cesium - Cs

Comprehensive data on the chemical element Cesium is provided on this page; including scores of properties, element names in many languages, most known nuclides of Cesium. 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.

Cesium Menu

• Cesium Page One
  • Overview of Cesium
  • Cesium's Name in Other Languages
  • Atomic Structure of Cesium
  • Chemical Properties of Cesium
  • Physical Properties of Cesium
  • Regulatory / Health
  • Who/When/Where/How
• Cesium Page Two
  • Nuclides / Isotopes
  • Potential Parent Nuclides
• Cesium Page Three
  • Common Chemical Compounds of Cesium

Overview of Cesium

• Atomic Number: 55
• Group: 1
• Period: 6
• Series: Alkali Metals

Cesium's Name in Other Languages

• Latin: Caesium
• Czech: Cesium
• Croatian: Cezij
• French: Césium
• German: Zäsium - s
• Italian: Cesio
• Norwegian: Cesium
• Portuguese: Césio
• Russian: Цеэий
• Spanish: Cesio
• Swedish: Cesium

Atomic Structure of Cesium

• Atomic Radius: 3.34Å
• Atomic Volume: 71.07cm³/mol
• Covalent Radius: 2.35Å
• Cross Section (Thermal Neutron Capture)σ_a/barns: 29
• Crystal Structure: Cubic body centered

  

• Electron Configuration:

  1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p⁶d¹⁰ 5s²p⁶ 6s¹

• Electrons per Energy Level: 2,8,18,18,8,1

  Shell Model
  

• Ionic Radius: 1.67Å
• Filling Orbital: 6s¹
• Number of Electrons (with no charge): 55
• Number of Neutrons (most common/stable nuclide): 78
• Number of Protons: 55
• Oxidation States: 1
• Valence Electrons: 6s¹

  Electron Dot Model
  

Chemical Properties of Cesium

• Electrochemical Equivalent: 4.9587g/amp-hr
• Electron Work Function: 2.14eV
• Electronegativity: 0.79 (Pauling); 0.86 (Allrod Rochow)
• Heat of Fusion: 2.092kJ/mol
• Incompatibilities:

• Ionization Potential
  • First: 3.894
  • Second: 25.1
• Valence Electron Potential (-eV): 8.62

Physical Properties of Cesium

• Atomic Mass Average: 132.9054
• Boiling Point: 944K 671°C 1240°F
• Coefficient of lineal thermal expansion/K^-1: 97E^-6
• Conductivity

  Electrical: 0.0489 10⁶/cm Ω
  Thermal: 0.359 W/cmK

• Density: 1.873g/cc @ 300K
• Description:

  Soft light silvery-white alkali metal.

• Elastic Modulus:
  • Bulk: 1.6/GPa
  • Rigidity: 0.65/GPa
  • Youngs: 1.7/GPa
• Enthalpy of Atomization: 78.2 kJ/mole @ 25°C
• Enthalpy of Fusion: 2.1 kJ/mole
• Enthalpy of Vaporization: 65.9 kJ/mole
• Flammablity Class:
• Freezing Point: see melting point
• Hardness Scale
  • Brinell: 0.14 MN m^-2
  • Mohs: 0.2
• Heat of Vaporization: 67.74kJ/mol
• Melting Point: 301.7K 28.55°C 83.39°F
• Molar Volume: 70.73 cm³/mole
• Physical State (at 20°C & 1atm): Solid
• Specific Heat: 0.24J/gK
• Vapor Pressure 2.5kPa

Regulatory / Health

• CAS Number
  • 7440-46-2
• RTECS: FK9225000
• OSHA Permissible Exposure Limit (PEL)
  • No limits set by OSHA
• OSHA PEL Vacated 1989
  • No limits set by OSHA
• NIOSH Recommended 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: 0.0038
  • Bone/p.p.m: 0.013-0.052
  • Liver/p.p.m: 0.04-0.05
  • Muscle/p.p.m: 0.07-1.6
  • Daily Dietary Intake: 0.004-0.03 mg
  • Total Mass In Avg. 70kg human: 6 mg

Who / Where / When / How

• Discoverer: Gustov R. Kirchoff, Robert Bunsen
• Discovery Location: Heidelberg Germany
• Discovery Year: 1860
• Name Origin:

  Latin: caesius (sky blue); its salts turn flames blue.

• Abundance of Cesium:
  • Earth's Crust/p.p.m.: 3
  • Seawater/p.p.m.: 0.0003
  • Atmosphere/p.p.m.: N/A
  • Sun (Relative to H=1E¹²): 80
• Sources of Cesium:

  Found in pollucite [(Cs₄Al₄Si₉O_{26).H2O] and as trace in lepidolite. World production is around 20 tons per year. Primary mining areas are in Bernic Lake (Manitoba, Canada), Bikita (Zimbabwe) and South-West Africa.}

• Uses of Cesium:

  Used as a 'getter' to remove air traces in vacuum tubes. Since it ionizes readily, it is used as an ion rocket motor propellant. Also used in photoelectric cells, atomic clocks, infared lamps.

• Additional Notes:

  Cesium can have very serious effects on the body if taken in excess.

Cesium Menu

• Cesium Page One
  • Overview of Cesium
  • Cesium's Name in Other Languages
  • Atomic Structure of Cesium
  • Chemical Properties of Cesium
  • Physical Properties of Cesium
  • Regulatory / Health
  • Who/When/Where/How
• Cesium Page Two
  • Nuclides / Isotopes
  • Potential Parent Nuclides
• Cesium Page Three
  • Common Chemical Compounds of Cesium

References

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.

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

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Kenneth Barbalace. Periodic Table of Elements - Cesium - Cs. EnvironmentalChemistry.com. 1995 - 2024. Accessed on-line: 12/21/2024
https://EnvironmentalChemistry.com/yogi/periodic/Cs.html
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