Symbol: Tl
Atomic number: 81
Atomic weight: 204.3833
Pure, unreacted thallium appears silvery-white and exhibits a metallic lustre. Upon reacting with air, it begins to turn bluish-grey and looks like lead. It is very malleable, and can be cut with a knife. There are two stable isotopes, and four radioisotopes, Tl-204 being the most stable with a half-life of 3.78 years. Thallium sulphate was used as a rodenticide. Thallium sulphine's conductivity changes with exposure to infrared light, this gives it a use in infrared detectors. Discovered by Sir William Crookes via spectroscopy. Its name comes from the Greek word thallos, which means green twig. Thallium and its compounds are toxic and can cause cancer.

Elements of periodic system. 2013.

  • Thallium — (pronEng|ˈθæliəm) is a chemical element with the symbol Tl and atomic number 81. [ [ thallium ] , Los Alamos National Laboratory. Retrieved November 21, 2006.] This soft gray malleable poor metal resembles …   Wikipedia

  • Thallium — Mercure ← Thallium → Plomb Indium …   Wikipédia en Français

  • THALLIUM — Du grec thallos , verdure. Symbole chimique: Tl Numéro atomique: 81 Masse atomique: 204,37 g Point de fusion: 303,5 0C Point d’ébullition: 1 457 0C Densité (à 20 0C): 11,85 Métal mou, facilement fusible, facilement oxydable dans l’air, découvert …   Encyclopédie Universelle

  • Thallium — Thal li*um, n. [NL., fr. Gr. ? young or green shoot or branch, twig. So called from a characteristic bright green line in its spectrum.] (Chem.) A rare metallic element of the aluminium group found in some minerals, as certain pyrites, and also… …   The Collaborative International Dictionary of English

  • Thallĭum — Thallĭum, ein von Crookes 1861 u. Lamy 1862 entdecktes Metall; es gleicht am meisten dem Blei, ist etwas weniger weiß als Silber, mit einem Stich ins Bläulichgraue, auf frischem Schnitte von lebhaftem Glanze; es ist sehr weich u. dehnbar, läßt… …   Pierer's Universal-Lexikon

  • Thallĭum — Tl, Metall, findet sich mit Kupfer, Silber und Selen im Crookesit (16–18,5 Proz.) und Berzelianit, in geringer Menge in manchen Schwefelund Kupferkiesen, in Zinkblende, im Lepidolith, im Glimmer von Zinnwald, in Corandit, Carnallit, im Badesalz… …   Meyers Großes Konversations-Lexikon

  • Thallium — Thallĭum (chem. Zeichen Tl), durch Spektralanalyse von Crookes und Lamy entdecktes Metall, zinnweiß, kristallinisch, fast so weich wie Natrium, vom spez. Gewicht 11,8, Atomgewicht 204,1 und dem Schmelzpunkt 290°, findet sich in geringen Mengen in …   Kleines Konversations-Lexikon

  • thallium — rare metallic element, 1861, Modern Latin, from Gk. thallos young shoot, green branch (see THALLUS (Cf. thallus)) + element name ending ium. So called by its discoverer, Sir William Crookes (1832 1919), from the green line in its spectrum by… …   Etymology dictionary

  • thallium — [thal′ē əm] n. [ModL: so named by CROOKES Sir William, its discoverer < Gr thallos, young, green shoot (< thallein: see THALIA) because of its green spectral line] a rare, poisonous, bluish gray, soft, metallic chemical element, used in… …   English World dictionary

  • Thallium — Eigenschaften …   Deutsch Wikipedia