Periodic Table of Elements

Element Rhodium - Rh

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

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Overview of Rhodium

Rhodium's Name in Other Languages

  • Latin: Rhodium
  • Czech: Rhodium
  • Croatian: Rodij
  • French: Rhodium
  • German: Rhodium - s
  • Italian: Rodio
  • Norwegian: Rhodium
  • Portuguese: Ródio
  • Russian: Родий
  • Spanish: Rodio
  • Swedish: Rodium

Atomic Structure of Rhodium

Chemical Properties of Rhodium

Physical Properties of Rhodium

  • Atomic Mass Average: 102.9055
  • Boiling Point: 4000K 3727°C 6741°F
  • Coefficient of lineal thermal expansion/K-1: 8.4E-6
  • Conductivity
    Electrical: 0.211 106/cm Ω
    Thermal: 1.5 W/cmK
  • Density: 12.41g/cc @ 300K
  • Description:
    Hard silver white metal that is unaffected by air and water up to 875K. It is also unaffected by acids but is attacked by multen alkalis.
  • Elastic Modulus:
    • Bulk: 276/GPa
    • Rigidity: 147/GPa
    • Youngs: 379/GPa
  • Enthalpy of Atomization: 556.5 kJ/mole @ 25°C
  • Enthalpy of Fusion: 21.76 kJ/mole
  • Enthalpy of Vaporization: 495.4 kJ/mole
  • Flammablity Class: Non-combustible solid (except as dust)
  • Freezing Point: see melting point
  • Hardness Scale
    • Brinell: 1100 MN m-2
    • Mohs: 6
    • Vickers: 1246 MN m-2
  • Heat of Vaporization: 493kJ/mol
  • Melting Point: 2239K 1966°C 3571°F
  • Molar Volume: 8.3 cm3/mole
  • Optical Reflectivity: 84%
  • Physical State (at 20°C & 1atm): Solid
  • Specific Heat: 0.242J/gK
  • Vapor Pressure = 0.633Pa@1966°C

Regulatory / Health

  • CAS Number
    • 7440-16-6
  • RTECS: VI9069000
  • OSHA Permissible Exposure Limit (PEL)
  • OSHA PEL Vacated 1989
  • NIOSH Recommended Exposure Limit (REL)
  • Routes of Exposure: Inhalation
  • Target Organs: 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: n/a
    • Bone/p.p.m: n/a
    • Liver/p.p.m: n/a
    • Muscle/p.p.m: n/a
    • Daily Dietary Intake: n/a
    • Total Mass In Avg. 70kg human: n/a

Who / Where / When / How

  • Discoverer: William H. Wollaston
  • Discovery Location: London England
  • Discovery Year: 1803
  • Name Origin:
    Greek: rhodon (rose). Its salts give a rosy solution.
  • Abundance of Rhodium:
    • Earth's Crust/p.p.m.: 0.0002
    • Seawater/p.p.m.: N/A
    • Atmosphere/p.p.m.: N/A
    • Sun (Relative to H=1E12): 25.1
  • Sources of Rhodium:
    Obtained as a by-product of nickel production. Rhodium is found in its native state in Montana USA. Around three tons of Rhodium are produced world wide on an annual basis.
  • Uses of Rhodium:
    Used as a coating to prevent wear on high quality science equipment and with platinum to make thermocouples. Also used in headlight reflectors, thelephone relays, fountain pen points and airplane spark plugs.
  • Additional Notes:

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