• Class: Metals
• Period: 6
• IUPAC group: 13
• Traditional: IIIb

• Discovered in: 1861 by Crookes
• Origin of name: Greek: thallos, (a green shoot or twig)
• Historical or alternate name:

Crooksite, lorandite, hutchinsonite & pyrites

Silvery grey, soft metal. Tarnishes in moist air. Reacts in heated moist air and in acids.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 0.006 ppm
• Sea water: 1e-5 ppm
• Metallic meteorite: 0.143 ppm
• ConTinental crust: 0.360 ppm
• Solar photosphere: 0.90 log of abundance
• Oceanic crust: 0.012 ppm
• Solar system: 0.184 relative to Si=1.0e6

   Hazards

Poison. Compounds highly toxic by inhalation or ingestion. Cumulative effects..

• Lower:
• Upper:0.01

Thallium Physical Properties

 Transitional Data

• State: Solid
• Density: 11.85 g/cm3

 Molar enthalpy

• Atomization: 182.845 kJ mol-1
• Fusion: 4.31 kJ mol-1
• Vaporization: 166.1 kJ mol-1

 Transition points

• MelTing point: 576.7 K
• Boiling point: 1730.0 K
• Critical temperature: 2329.0 K

 Molar properties

• Atomic weight: 204.3833 g/mole
• Molar volume: 17.322 cm3 mol-1

 Crystal structure sequence

hexagonal-close-packed <503 K < body-centered-cubic < melTing point

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 64.18
  • Heat Capacity 26.32

• State: gas
  • Enthalpy 182.21
  • Gibbs function 147.41
  • Entropy 180.963
  • Heat Capacity 20.786

 Miscellaneous physical

• Electrical resistivity: 18.0 µ-ohms/cm
• Debye temperature: 78.5 K
• Thermal conductivity: 46.1 W / m / K
• Coefficient of linear expansion: 30.0Coef. per K
• Mass magnetic susceptibility: -3.13e-9
• X-ray diffraction mass absorption coefficients:
• CuK: 224 (µ/p)/cm2 g-1
• MoK: 119 (µ/p)/cm2 g-1

Thallium Chemical Properties

 Chemical basics:

• Oxidation states: +1 +3
• Molecular wt: 204.3833 g/mole

 Radii

• Covalent: 155 pm
• Atomic: 171.0 pm
• Van der Waals: pm

 Ions:

• ion: +1 pm 150.0
• ion: +3 pm 88.5

 Covalent bonds

 Effective nuclear charge

• Slater: 5.00
• Clementi: 12.5
• Froese-Fischer: 13.50

 Electronegativity

• Pauling: 1.8
• Allred-Rochow: 1.44

 Standard reactions

Thallium Nuclear Properties

• Known 28
• Listed 4

• Known 191 - 210
• Listed 202 - 205

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 12.20 days
  • Decay mode: E.C.,
  • Source:
• Notes

• % Occ.:Natural 29.524%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 1/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 2/0
• Radioisotopes:
  • Half-life: 3.78 years
  • Decay mode: Beta- E.C.,
  • Source:
• Notes

• % Occ.:Natural 70.476%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 1/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• Isotope Cross-section 3.4±0.5 barns

• Absolute sensitivity: 5.51e-2 1H=1.0
• Relative sensitivity: 0.18 1H=1.0
• Receptivity: 289 13C=1.0
• Magnetogyric ratio: 15.3078e7 rad / T / s
• Quadropole moment: m2
• Frequency: 57.149 MHz
• Reference: TlNO3

Thallium Energy Properties

Electrons

• Ground state electron configuration: [Xe] 4f14 5d10 6s2 6p1
• Electron affinity: 30 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels