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Periodic Table of Elements

Element Lanthanum – La

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

Lanthanum Menu

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

Overview of Lanthanum

• Atomic Number:57
• Group: 3
• Period: 6
• Series: Lanthanides

Lanthanum's Name in Other Languages

• Latin: Lanthanium
• Czech: Lanthan
• Croatian: Lantan
• French: Lanthane
• German: Lanthan - r
• Italian: Lantanio
• Norwegian: Lantan
• Portuguese: Lantânio
• Russian:
• Spanish: Lantano
• Swedish: Lantan

Atomic Structure of Lanthanum

• Atomic Radius: 2.74Å
• Atomic Volume: 20.73cm³/mol
• Covalent Radius: 1.69Å
• Cross Section (Thermal Neutron Capture) _a/barns: 8.98
• Crystal Structure: Hexagonal

  

• Electron Configuration:

  1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p⁶d¹⁰ 5s²p⁶d¹ 6s²

• Electrons per Energy Level: 2,8,18,18,9,2

  Shell Model
  

• Ionic Radius: 1.061Å
• Filling Orbital: 5d¹
• Number of Electrons (with no charge): 57
• Number of Neutrons (most common/stable nuclide): 82
• Number of Protons: 57
• Oxidation States: 3
• Valence Electrons: 5p¹ 6s²

  Electron Dot Model
  

Chemical Properties of Lanthanum

• Electrochemical Equivalent: 1.7275g/amp-hr
• Electron Work Function: 3.5eV
• Electronegativity: 1.1 (Pauling); 1.08 (Allrod Rochow)
• Heat of Fusion: 6.2kJ/mol
• Incompatibilities:

• Ionization Potential
  • First: 5.58
  • Second: 11.059
  • Third: 19.174
• Valence Electron Potential (-eV): 40.71

Physical Properties of Lanthanum

• Atomic Mass Average: 138.9055
• Boiling Point: 3730K 3457°C 6255°F
• Coefficient of lineal thermal expansion/K^-1: 4.9E^-6
• Conductivity

  Electrical: 0.0126 10⁶/cm
  Thermal: 0.135 W/cmK

• Density: 6.15g/cc @ 300K
• Description:

  Soft silvery white transition metal that rapidly tarnishes in air. It will burn easily if ignited.

• Elastic Modulus:
  • Bulk: 28/GPa
  • Rigidity: 14.9/GPa
  • Youngs: 37.9/GPa
• Enthalpy of Atomization: 431 kJ/mole @ 25°C
• Enthalpy of Fusion: 6.2 kJ/mole
• Enthalpy of Vaporization: 399.6 kJ/mole
• Flammablity Class:
• Freezing Point: see melting point
• Hardness Scale
  • Brinell: 363 MN m^-2
  • Mohs: 2.5
  • Vickers: 491 MN m^-2
• Heat of Vaporization: 414kJ/mol
• Melting Point: 1193K 920°C 1688°F
  
• Molar Volume: 22.6 cm³/mole
• Physical State (at 20°C & 1atm): Solid
• Specific Heat: 0.19J/gK
• Vapor Pressure = 1.33E-07Pa@920°C

Regulatory / Health

• CAS Number
  • 7439-91-0
• 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: n/a
  • Bone/p.p.m: <0.08
  • Liver/p.p.m: 0.3
  • Muscle/p.p.m: 0.0004
  • Daily Dietary Intake: n/a
  • Total Mass In Avg. 70kg human: 0.8 mg
• Discovery Year: 1839
• Name Origin:

  Greek: lanthanein (to lie hidden).

• Abundance of Lanthanum:
  • Earth's Crust/p.p.m.: 32
  • Seawater/p.p.m.:
    • Atlantic Suface: 0.0000018
    • Atlantic Deep: 0.0000038
    • Pacific Surface: 0.0000026
    • Pacific Deep: 0.0000069
  • Atmosphere/p.p.m.: N/A
  • Sun (Relative to H=1E¹²): 13.5
• Sources of Lanthanum:

  Found with rare earths in monazite and bastnasite. Around 12,500 tons are produced world wide each year. Primary mining areas are USA, Brazil, India, Sri Lanka, Australia.

• Uses of Lanthanum:

  Because it gives glass refractive properties, it is used in expensive camera lenses. Also used in lighter flints, battery electrodes and catalytic converters.

• Additional Notes:

[Last update: 2/22/2007]

Lanthanum Menu

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

Related Resources

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• Molar Mass Calculations and Javascript Calculator
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• 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 - Lanthanum – La. EnvironmentalChemistry.com. 1995 - 2009. Accessed on-line: 11/8/2009
http://EnvironmentalChemistry.com/yogi/periodic/La.html
.