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Atomic: M.A.C. | Reference
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Thallium
Electrons per shell 2,8,18,32,18,3
Electron Configuration [Xe] 4f14 5d10 6s2 6p1 open electron config
Ground state 2°1/2
Atomic Volume 17.2 cm3 mol-1
Electronegativity 1.62
Magnetic ordering No data
Mass magnetic susceptibility -3 x 10-9
Molar magnetic susceptibility -6.13 x 10-10
Speed of sound 818 m s-1
Thermal Properties
Enthalpy of Atomization 179.9 kJ mol-1 @25°C
Enthalpy of Fusion 4.31 kJ mol-1
Enthalpy of Vaporisation 166.1 kJ mol-1
Heat Capacity 26.32 J mol-1 K-1
Thermal Conductivity 46.1 W m-1 K-1
Thermal Expansion 29.9 μm m-1 K-1
Hardness
Brinell hardness 26.4 MPa
Mohs hardness 1.2
Elastic Properties
Bulk modulus 43 GPa
Poisson ratio 0.45
Shear modulus 2.8 GPa
Young's modulus 8 GPa
Electrical Properties
Electrical resistivity 1.5 x 10-7 Ω m
Electrical conductivity 0.0617 106/cm Ω
Chemical Properties
Electrochemical Equivalent 7.625 g Ah-1
Electron Work Function 3.84 eV
Valence Electron Potential (-eV) 9.6
Ionization Potential  
First 6.108
Second 20.428
Third 29.829
Energy Levels
Kα1 (intensity 100) 72.8715 KeV
Kα2 (intensity 50) 70.8319 KeV
Kβ1 (intensity 0) 82.576 KeV
Lα1 (intensity 100) 10.2685 KeV
Lα2 (intensity 10) 10.1728 KeV
Lβ1 (intensity 36) 12.2133 KeV
Lβ2 (intensity 20) 12.2715 KeV
Lβ3 (intensity 6.3) 12.3875 KeV
Lβ4 (intensity 4) 11.9297 KeV
Lγ1 (intensity 6) 14.2915 KeV
Lγ2 (intensity 2.7) 14.62 KeV
Lγ3 (intensity 2) 10.99 KeV
Ll (intensity 4.5) 8.9523 KeV
Atomic Radii
Empirical 190 pm
Bohr Radius 156 pm
Covalent Radius 148 pm
Van der Waals 196 pm
Triple covalent 150 pm
Metallic 170 pm
Oxidation States
Main Tl+1
Other Tl+3
Ionisation Energies (kJ mol-1) show graph
M - M+ 589.3
M+ - M2+ 1971
M2+ - M3+ 2878
M3+ - M4+ 4900
M4+ - M5+ 6100
M5+ - M6+ 8300
M6+ - M7+ 9500
M7+ - M8+ 11300
M8+ - M9+ 1400
M9+ - M10+ 16000
Covalent Bonds (kJ mol-1)
Tl+1-H 185
Tl+3-C 125
Tl+3-O 375
Tl+3-F 460
Tl+3-Cl 368
Tl-Tl 63
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 882 977 1097 1252 1461 1758
Crystal Structure
Structure Hexagonal close packed
a = 345.66 pm
b = 345.66 pm
c = 552.48 pm
α = 90°
β = 90°
γ = 120°