• Class: Halogens
• Period: 5
• IUPAC group: 17
• Traditional: VIIb

• Discovered in: 1811 by Courtois
• Origin of name: Greek: iodes, (violet)
• Historical or alternate name:

Caliche, sea water & sea brines

Shiny violet-black solid with characteristic odor. Sublimes easily.

• Atmosphere: ~0.0 ppm
• Primitive mantle: ~0.0 ppm
• Sea water: 0.05 ppm
• Metallic meteorite: 0.430 ppm
• ConTinental crust: 0.5 ppm
• Solar photosphere: ~0.0 log of abundance
• Oceanic crust: ~0.0 ppm
• Solar system: 0.90 relative to Si=1.0e6

   Hazards

Harmful vapor. Irritant. Causes burns on inhalation or skin contact..

• Lower:0.01
• Upper:1.0

Iodine Physical Properties

 Transitional Data

• State: Solid
• Density: 4.93 g/cm3

 Molar enthalpy

• Atomization: 107.240 kJ mol-1
• Fusion: 15.27 kJ mol-1
• Vaporization: 41.67 kJ mol-1

 Transition points

• MelTing point: 386.7 K
• Boiling point: 457.50 K
• Critical temperature: 819.0 K

 Molar properties

• Atomic weight: 126.90447 g/mole
• Molar volume: 25.873 cm3 mol-1

 Crystal structure sequence

orthorhombic

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 116.135
  • Heat Capacity 54.438

• State: gas (I2)
  • Enthalpy 62.438
  • Gibbs function 19.327
  • Entropy 260.69
  • Heat Capacity 36.90

• State: gas (atoms)
  • Enthalpy 106.838
  • Gibbs function 70.250
  • Entropy 180.791
  • Heat Capacity 20.786

 Miscellaneous physical

• Electrical resistivity: 1.3 E15 µ-ohms/cm
• Debye temperature: K
• Thermal conductivity: 0.449 W / m / K
• Coefficient of linear expansion: Coef. per K
• Mass magnetic susceptibility: -4.40e-9
• X-ray diffraction mass absorption coefficients:
• CuK: 294 (µ/p)/cm2 g-1
• MoK: 37.1 (µ/p)/cm2 g-1

Iodine Chemical Properties

 Chemical basics:

• Oxidation states: -1 +1 +5 +7
• Molecular wt: 126.90447 g/mole

 Radii

• Covalent: 133.3 pm
• Atomic: 133.0 pm
• Van der Waals: 215 pm

 Ions:

• ion: -1 pm 220.0
• ion: +5 pm 95.0
• ion: +7 pm 53.0

 Covalent bonds

 Effective nuclear charge

• Slater: 7.60
• Clementi: 11.61
• Froese-Fischer: 14.59

 Electronegativity

• Pauling: 2.5
• Allred-Rochow: 2.21

 Standard reactions

Iodine Nuclear Properties

• Known 24
• Listed 5

• Known 117 - 139
• Listed 125 - 131

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 60.10 days
  • Decay mode: E.C.,
  • Source: reactor
• Notes med

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 13.00 days
  • Decay mode: E.C., Beta- Beta+
  • Source: reactor
• Notes

• % Occ.:Natural 100.0%
• Mossbauer NRA: 9.23
• Nuclear spin/Quantum no.: 5/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA: 4.44 *
• Nuclear spin/Quantum no.: 7/2
• Radioisotopes:
  • Half-life: 15.70 E6 years
  • Decay mode: Beta-
  • Source: reactor
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 8.02 days
  • Decay mode: Beta-
  • Source: reactor
• Notes med

• Isotope Cross-section 6.2±0.2 barns

• Absolute sensitivity: 9.34e-2 1H=1.0
• Relative sensitivity: 9.34e-2 1H=1.0
• Receptivity: 530 13C=1.0
• Magnetogyric ratio: 5.3525e7 rad / T / s
• Quadropole moment: -0.79e-28 m2
• Frequency: 20.007 MHz
• Reference: NaI

Iodine Energy Properties

Electrons

• Ground state electron configuration: [Kr] 4d10 5s2 5p5
• Electron affinity: 295.3 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels