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Periodic Table of Elements

Element Arsenic – As

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

Arsenic Menu

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

Overview of Arsenic

• Atomic Number:33
• Group: 15
• Period: 4
• Series: Metalloids (Nonmetal)

Arsenic's Name in Other Languages

• Latin: Arsenicum
• Czech: Arzen
• Croatian: Arsen
• French: Arsenic
• German: Arsenic - r
• Italian: Arsenico
• Norwegian: Arsen
• Portuguese: Arsênio
• Russian:
• Spanish: Arsénico
• Swedish: Arsenik

Atomic Structure of Arsenic

• Atomic Radius: 1.33Å
• Atomic Volume: 13.1cm³/mol
• Covalent Radius: 1.2Å
• Cross Section (Thermal Neutron Capture)_a/barns: 4.3
• Crystal Structure: Rhombohedral

  

• Electron Configuration:

  1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p³

• Electrons per Energy Level: 2,8,18,5

  Shell Model
  

• Ionic Radius: 0.58Å
• Filling Orbital: 4p³
• Number of Electrons (with no charge): 33
• Number of Neutrons (most common/stable nuclide): 42
• Number of Protons: 33
• Oxidation States: ±3,5
• Valence Electrons: 4s²p³

  Electron Dot Model
  

Chemical Properties of Arsenic

• Electrochemical Equivalent: 0.93177g/amp-hr
• Electron Work Function: 3.75eV
• Electronegativity: 2.18 (Pauling); 2.2 (Allrod Rochow)
• Heat of Fusion: 369.9kJ/mol
• Incompatibilities:

  halogenated compounds, rhubidium, carbide

• Ionization Potential
  • First: 9.81
  • Second: 18.633
  • Third: 28.351
• Valence Electron Potential (-eV): 74

Physical Properties of Arsenic

• Atomic Mass Average: 74.92159
• Boiling Point: 876K 603°C 1117°F
• Coefficient of lineal thermal expansion/K^-1: 4.7E^-6
• Conductivity

  Electrical: 0.0345 10⁶/cm
  Thermal: 0.502 W/cmK

• Density: 5.72g/cc @ 300K
• Description:

  Gray brittle non-metal flakes.

• Enthalpy of Atomization: 301.3 kJ/mole @ 25°C
• Enthalpy of Fusion: 24.44 kJ/mole
• Enthalpy of Vaporization: 34.76 kJ/mole
• Flammablity Class:
• Freezing Point: see melting point
• Hardness Scale
  • Brinell: 1440 MN m^-2
  • Mohs: 3.5
• Heat of Vaporization: 34.76kJ/mol
• Melting Point: 1081K 808°C 1486°F
  
• Molar Volume: 13.08 cm³/mole
• Optical Refractive Index: 1.001552
• Physical State (at 20°C & 1atm): Solid
• Specific Heat: 0.33J/gK

Regulatory / Health

• CAS Number
  • 7740-38-2
• UN/NA ID and ERG Guide Number
  • UN1557  
• RTECS: CG0525000
• NFPA 704
  • Health: 3
  • Fire: 2
  • Reactivity:
  • Special Hazard:
• OSHA Permissible Exposure Limit (PEL)
  • TWA: 0.5 mg/m³
• OSHA PEL Vacated 1989
• NIOSH Recommended Exposure Limit (REL)
  • No limits set by NIOSH
• Routes of Exposure: Inhalation; Ingestion; Skin and/or eye contact
  
• Target Organs: Skin, respiratory system, kidneys, central nervous system, liver, gastrointestinal tract, reproductive 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: 0.0017-0.09
  • Bone/p.p.m: 0.08-1.6
  • Liver/p.p.m: 0.023-1.61
  • Muscle/p.p.m: 0.009-0.65
  • Daily Dietary Intake: 0.04-1.4 mg
  • Total Mass In Avg. 70kg human: 0.5-15 mg

Who / Where / When / How

• Discoverer: Alberts Magna
• Discovery Location: Unknown
• Discovery Year: 1250
• Name Origin:

  Greek: arsenikos (male); Latin: arsenicum.

• Abundance of Arsenic:
  • Earth's Crust/p.p.m.: 1.5
  • Seawater/p.p.m.:
    • Atlantic Suface: 0.00145
    • Atlantic Deep: 0.00153
    • Pacific Surface: 0.00145
    • Pacific Deep: 0.00175
  • Atmosphere/p.p.m.: N/A
  • Sun (Relative to H=1E¹²): N/A
• Sources of Arsenic:

  Found in mispickel (arsenopyrite). Mainly produced as a by-product of refining certain sulfide ores. Annual world wide production is around 47,000 tons (As2O3).

• Uses of Arsenic:

  Used as a deadly poison, in shotgun pellets, metal for mirrors, glass, lasers, light-emitting diodes (LED) and in semiconductors.

• Additional Notes:

  Arsenic is a carcinogen, associated with lung cancer when inhaled. Contact with skin can result in skin cancer. Also damage to intestines and liver. Toxic when ingested. Found in pesticides and wood preservatives. It is naturally occurring in many household products. It may have been known to ancient civilizations, but was probably first isolated by Magnus who lived between 1193-1280. Many sources reference 1250 as the year of discovery but this may be speculation.

[Last update: 2/22/2007]

Arsenic Menu

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

Related Resources

• Anatomy of the Atom
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• Molarity, Molality and Normality
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• 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 - Arsenic – As. EnvironmentalChemistry.com. 1995 - 2009. Accessed on-line: 11/8/2009
http://EnvironmentalChemistry.com/yogi/periodic/As.html
.