Thallium is a soft bendable and shapeable element that turns a bluish-gray color when exposed to the atomosphere. Thallium's atomic number is 81 and is in group 13 on the periodic table. Thallium was discovered in 1861 in London by a British chemist named crookes. Thallium's atomic mass is 204.4, it has 25 isotopes.
Thallium is odorless, tasteless, and poisonous.
Thallium is used to exterminate rodents and ants. Thallium activated soudiam iodide crystals on a photomultiplier tubes are used in a few scintillition counter to detect gamma radition. Thallium alloyed with mercury forms a fluid metal that freezes at -60 degrees it boils at 1746 degrees and melts at 577 degrees. Thallium forms a hydroxide in water and is soluble in nitric acid and sulfuric acid. Thallium has a high index of refraction and is important in the manufacture of several types of optical glass.