Thallium Facts - Periodic Table of the Elements

Thallium Facts - Periodic Table of the Elements ThalliumBasic Facts Atomic Number: 81 Symbol: Tl Atomic Weight: 204.3833 Discovery: Crookes 1861 Electron Configuration: [Xe] 4f14 5d10 6s2 6p1 Element Classification: metal Discovered By: Sir William Crookes Discovery Date: 1861 (England) Name Origin: Greek: thallos (green twig), named for a bright green line in its spectrum. Thallium Physical Data Density (g/cc): 11.85 Melting Point (Â °K): 576.6 Boiling Point (Â °K): 1730 Appearance: soft bluish-gray metal Atomic Radius (pm): 171 Atomic Volume (cc/mol): 17.2 Covalent Radius (pm): 148 Ionic Radius: 95 (3e) 147 (1e) Specific Heat (20Â °C J/g mol): 0.128 Fusion Heat (kJ/mol): 4.31 Evaporation Heat (kJ/mol): 162.4 Thermal Conductivity: 46.1 J/m-sec-deg Debye Temperature (Â °K): 96.00 Pauling Negativity Number: 1.62 First Ionizing Energy (kJ/mol): 588.9 Oxidation States: 3, 1 Lattice Structure: hexagonal Lattice Constant (Ã…): 3.460 Lattice C/A Ratio: 1.599 Uses: infrared detectors, photomultipliers Source: obtained as a by-product of Zn/Pb smelting References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Langes Handbook of Chemistry (1952) Periodic Table of the Elements