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Periodic Table of Elements

Element Actinium - Ac

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

Actinium Menu

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

Overview of Actinium

• Atomic Number: 89
• Group: 3
• Period: 7
• Series: Actinides

Actinium's Name in Other Languages

• Latin: Actinium
• Czech: Aktinium
• Croatian: Aktinij
• French: Actinium
• German: Aktinium - s
• Italian: Attinio
• Norwegian: Actinium
• Portuguese: Actínio
• Russian: Актиний
• Spanish: Actínio
• Swedish: Aktinium

Atomic Structure of Actinium

• Atomic Radius: 1.88Å
• Atomic Volume: 22.54cm³/mol
• Covalent Radius:
• Cross Section (Thermal Neutron Capture)σ_a/barns: 515
• Crystal Structure: Cubic face centered

  

• Electron Configuration:

  1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p⁶d¹⁰f¹⁴ 5s²p⁶d¹⁰ 6s²p⁶d¹ 7s²

• Electrons per Energy Level: 2,8,18,32,18,9,2

  Shell Model
  

• Ionic Radius: 1.119Å
• Filling Orbital: 6d¹
• Number of Electrons (with no charge): 89
• Number of Neutrons (most common/stable nuclide): 138
• Number of Protons: 89
• Oxidation States: 3
• Valence Electrons: 6d¹ 7s²

  Electron Dot Model
  

Chemical Properties of Actinium

• Electrochemical Equivalent: 2.82347g/amp-hr
• Electron Work Function:
• Electronegativity: 1.1 (Pauling); 1 (Allrod Rochow)
• Heat of Fusion: 62kJ/mol
• Incompatibilities:

• Ionization Potential
  • First: 5.17
  • Second: 12.126
• Valence Electron Potential (-eV): 38.6

Physical Properties of Actinium

• Atomic Mass Average: 227.0728
• Boiling Point: 3473K 3200°C 5792°F
• Coefficient of lineal thermal expansion/K^-1: 14.9E^-6
• Conductivity

  Electrical:
  Thermal: 0.12 W/cmK

• Density: 10.07g/cc @ 300K
• Description:

  Silvery-white radioactive metal that glows in the dark

• Enthalpy of Atomization: 301 kJ/mole @ 25°C
• Flammablity Class:
• Freezing Point: see melting point
• Heat of Vaporization: kJ/mol
• Melting Point: 1323K 1050°C 1922°F
• Molar Volume: 22.54 cm³/mole
• Physical State (at 20°C & 1atm): Solid
• Specific Heat: 0.12J/gK

Regulatory / Health

• CAS Number
  • 7440-34-8
• NFPA 704
  • Health:
  • Fire:
  • Reactivity:
  • Special Hazard: Radioactive<
  • 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: nil
    • Bone/p.p.m: nil
    • Liver/p.p.m: nil
    • Muscle/p.p.m: nil
    • Daily Dietary Intake: nil
    • Total Mass In Avg. 70kg human: nil

  Who / Where / When / How

  • Discoverer: André Debierne
  • Discovery Location: Paris France
  • Discovery Year: 1899
  • Name Origin:

    Greek: aktinos (ray).

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

    Extremely rare, found in all uranium ores. Usually obtained by treating radium with neutrons in a reactor. Total world production probably less than one gram.

  • Uses of Actinium:

    Used as a source of neutrons and for thermoelectric power. Not commercially available.

  • Additional Notes:

  Actinium Menu

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

  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.

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