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THALLIUM (81Tl204.3833)

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Element Description

Thallium was discovered spectroscopically and is named for its green spectral line. It has a metallic luster when first exposed to air, but quickly develops a bluish-gray tone that resembles lead. Thallium is very soft and malleable, inelastic, and heavy. It occurs as a mixture of two isotopes.

Property Name Property Value Property Name Property Value
Atomic Code (81Tl204.3833) Atomic Volume 17.2W/D
CAS # 7440-28-0 First Ionization Energy 141K-cal/g-mole
Electronegativity 1.8Pauling's
Melting Point 303.5°C Covalent Radius 1.48Angstroms
Boiling Point 1457°C Brinell Hardness 2
Density 11.85g/cm3 Linear Coefficient of Expansion 28x10-6K-1
Themal Conductivity 0.093cal/cm2/cm/s/°C Electrical Resistivity 18µΩ-cm
Specific Heat @ 20°C 0.031cal/g°C Crystal Structure Hexagonal
Heat of Fusion 5.04cal/g Tensile Strength 1300psi
Heat of Vaporization 190cal/g


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