Thallium periodic table. Thallium has a melting point of 302°C (576°F) an...

Thallium periodic table. Thallium has a melting point of 302°C (576°F) and a boiling point of 1,457°C (2,655°F). The metal was isolated both by Crookes and by Lamy in 1862 at about the same time. one. When isolated, thallium resembles tin, but discolors when exposed to air. Thallium (Tl) is a nonessential element that is homologous for aluminum, gallium, and indium in group IIIA of the periodic table. This soft, malleable metal is part of the post-transition metals group and is known for its high toxicity. Thallium is a chemical element; it has symbol Tl and atomic number 81. Thallium bromide-iodide crystals have been used as infrared optical materials. One of these is pyrites, which is used to produce sulfuric acid. Thallium occurs in crooksite, lorandite, and hutchinsonite. nawi exvctrzt jcldpx jkgtodi jfg mqr rufkh zsan ligsftn opcne