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Technical data for Thallium

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Overview
NameThallium
SymbolTl
Atomic Number81
Atomic Weight204.38
Density11.85 g/cm3
Melting Point304 °C
Boiling Point1473 °C

Thermal properties
PhaseSolid
Melting Point304 °C
Boiling Point1473 °C
Absolute Melting Point577 K
Absolute Boiling Point1746 K
Critical PressureN/A
Critical TemperatureN/A
Heat of Fusion4.2 kJ/mol
Heat of Vaporization165 kJ/mol
Specific Heat129 J/(kg K)[note]
Adiabatic IndexN/A
Neel PointN/A
Thermal Conductivity46 W/(m K)
Thermal Expansion0.0000299 K-1

Bulk physical properties
Density11.85 g/cm3
Density (Liquid)11.22 g/cm3
Molar Volume0.0000172473
Brinell Hardness26.4 MPa
Mohs Hardness1.2
Vickers HardnessN/A
Bulk Modulus43 GPa
Shear Modulus2.8 GPa
Young Modulus8 GPa
Poisson Ratio0.45
Refractive IndexN/A
Speed of Sound818 m/s
Thermal Conductivity46 W/(m K)
Thermal Expansion0.0000299 K-1

Reactivity
Valence3
Electronegativity1.62
ElectronAffinity19.2 kJ/mol
Ionization Energies
589.4, 1971, 2878 kJ/mol

Health and Safety
DOT Hazard ClassN/A
DOT Numbers1707
RTECS Number
RTECSXG3425000
NFPA LabelN/A

Classifications
Alternate NamesNone
Names of AllotropesNone
Blockp
Group13
Period6
SeriesPoor Metal
Electron Configuration[Xe]6s24f145d106p1
ColorSilver
Discovery
1861 in The United Kingdom
Gas phaseN/A
CAS NumberCAS7440-28-0
CID Number
CID5359464
RTECS Number
RTECSXG3425000

Electrical properties
Electrical TypeConductor
Electrical Conductivity6.7×106 S/m
Resistivity1.5×10-7 m Ω
Superconducting Point2.38

Magnetic properties
Magnetic TypeDiamagnetic
Curie PointN/A
Mass Magnetic Susceptibility-3×10-9 m3/Kg
Molar Magnetic Susceptibility-6.13×10-10 m3/mol
Volume Magnetic Susceptibility-0.0000356

Abundances
% in Universe5×10-8%
% in Sun1×10-7%
% in Meteorites7.9×10-6%
% in Earth's Crust0.000054%
% in Oceans1×10-10%
% in HumansN/A

Atomic dimensions and structure
Atomic Radius156 pm
Covalent Radius145 pm
Van der Waals Radius196 pm
Crystal StructureSimple Hexagonal
Lattice Angles
π/2, π/2, 2 π/3
Lattice Constants
345.66, 345.66, 552.48 pm
Space Group NameP63/mmc
Space Group Number194

Nuclear Properties
Half-LifeStable
LifetimeStable
Decay ModeN/A
Quantum Numbers2P1/2
Neutron Cross Section3.4
Neutron Mass Absorption0.00059
Known Isotopes
176Tl, 177Tl, 178Tl, 179Tl, 180Tl, 181Tl, 182Tl, 183Tl, 184Tl, 185Tl, 186Tl, 187Tl, 188Tl, 189Tl, 190Tl, 191Tl, 192Tl, 193Tl, 194Tl, 195Tl, 196Tl, 197Tl, 198Tl, 199Tl, 200Tl, 201Tl, 202Tl, 203Tl, 204Tl, 205Tl, 206Tl, 207Tl, 208Tl, 209Tl, 210Tl, 211Tl, 212Tl
Stable Isotopes
203Tl, 205Tl
Isotopic Abundances
203Tl29.524%
205Tl70.476%


Notes on the properties of Thallium:

Specific Heat: Value given for solid phase.

Up to date, curated data provided by Mathematica's ElementData function from Wolfram Research, Inc.

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