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Periodic Table of Elements

Element Cobalt – Co

Comprehensive data on the chemical element Cobalt is provided on this page; including scores of properties, element names in many languages, most known nuclides of Cobalt. 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 studies. Using the "Periodic Table of Elements Quick Navigation" graphic at the bottom of the sidebar menu, one can quickly jump from chemical element to chemical element.

Cobalt Menu

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

Overview of Cobalt

• Atomic Number:27
• Group: 9
• Period: 4
• Series: Transition Metals

Cobalt's Name in Other Languages

• Latin: Cobaltum
• Czech: Kobalt
• Croatian: Kobalt
• French: Cobalt
• German: Kobalt - r
• Italian: Cobalto
• Norwegian: Kobolt
• Portuguese: Cobalto
• Russian:
• Spanish: Cobalto
• Swedish: Kobolt

Atomic Structure of Cobalt

• Atomic Radius: 1.67Å
• Atomic Volume: 6.7cm³/mol
• Covalent Radius: 1.16Å
• Cross Section (Thermal Neutron Capture)_a/barns: 37.2
• Crystal Structure: Hexagonal

  

• Electron Configuration:

  1s² 2s²p⁶ 3s²p⁶d⁷ 4s²

• Electrons per Energy Level: 2,8,15,2

  Shell Model
  

• Ionic Radius: 0.745Å
• Filling Orbital: 3d⁷
• Number of Electrons (with no charge): 27
• Number of Neutrons (most common/stable nuclide): 32
• Number of Protons: 27
• Oxidation States: 2,3
• Valence Electrons: 3d⁷ 4s²

Chemical Properties of Cobalt

• Electrochemical Equivalent: 1.0994g/amp-hr
• Electron Work Function: 5eV
• Electronegativity: 1.88 (Pauling); 1.7 (Allrod Rochow)
• Heat of Fusion: 16.19kJ/mol
• Incompatibilities:

  Strong oxidizers, ammonium nitrate

• Ionization Potential
  • First: 7.86
  • Second: 17.06
  • Third: 33.5
• Valence Electron Potential (-eV): 38.7

Physical Properties of Cobalt

• Atomic Mass Average: 58.9332
• Boiling Point: 3143K 2870°C 5198°F
• Coefficient of lineal thermal expansion/K^-1: 13.36E^-6
• Conductivity

  Electrical: 0.172 10⁶/cm
  Thermal: 1 W/cmK

• Density: 8.9g/cc @ 300K
• Description:

  Tough silver-white transition metal.

• Elastic Modulus:
  • Bulk: 181.5/GPa
  • Rigidity: 82/GPa
  • Youngs: 211/GPa
• Enthalpy of Atomization: 26.8 kJ/mole @ 25°C
• Enthalpy of Fusion: 15.23 kJ/mole
• Enthalpy of Vaporization: 382.4 kJ/mole
• Flammablity Class: Non-combustible solid (except as dust)
• Freezing Point: see melting point
• Hardness Scale
  • Brinell: 700 MN m^-2
  • Mohs: 5
  • Vickers: 1043 MN m^-2
• Heat of Vaporization: 376.5kJ/mol
• Melting Point: 1768K 1495°C 2723°F
  
• Molar Volume: 6.61 cm³/mole
• Optical Reflectivity: 67%
• Physical State (at 20°C & 1atm): Solid
• Specific Heat: 0.42J/gK
• Vapor Pressure = 175Pa@1495°C

Regulatory / Health

• CAS Number
  • 7440-48-4
• RTECS: GF8750000
• OSHA Permissible Exposure Limit (PEL)
  • TWA: 0.1 mg/m³
• OSHA PEL Vacated 1989
  • TWA: 0.05 mg/m³
• NIOSH Recommended Exposure Limit (REL)
  • TWA: 0.05 mg/m³
  • IDLH: 20 mg/m³
• Routes of Exposure: Inhalation; Ingestion; Skin and/or eye contact
  
• Target Organs: Skin, respiratory system
  
• 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: 0.0002-0.04
  • Bone/p.p.m: 0.01-0.04
  • Liver/p.p.m: 0.06-1.1
  • Muscle/p.p.m: 0.028-0.65
  • Daily Dietary Intake: 0.005-1.8 mg
  • Total Mass In Avg. 70kg human: 3 mg

Who / Where / When / How

• Discoverer: George Brandt
• Discovery Location: Stockholm Sweden
• Discovery Year: 1735
• Name Origin:

  German: kobalt or kobold (evil spirit); Greek: cobalos (mines).

• Abundance of Cobalt:
  • Earth's Crust/p.p.m.: 20
  • Seawater/p.p.m.:
    • Atlantic Suface: N/A
    • Atlantic Deep: N/A
    • Pacific Surface: 0.0000069
    • Pacific Deep: 0.0000011
  • Atmosphere/p.p.m.: N/A
  • Sun (Relative to H=1E¹²): 79400
• Sources of Cobalt:

  Occurs in compounds with arsenic, oxygen and sulfur as in cobaltine (CoAsS) and linneite (Co₃S₄). Annual world production is around 17,000 tons. Primary mining areas are in Zaire, Morocco, Sweden and Canada.

• Uses of Cobalt:

  Used in many hard alloys; for magnets, ceramics and special glasses. Also used in permanent magnets, razor blades and catalitic converters. Cobalt-60 is used in cancer therapy.

• Additional Notes:

[Last update: 2/22/2007]

Cobalt Menu

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

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 - Cobalt – Co. EnvironmentalChemistry.com. 1995 - 2009. Accessed on-line: 11/20/2009
http://EnvironmentalChemistry.com/yogi/periodic/Co.html
.