Thallium - Wikipedia Thallium is a chemical element; it has symbol Tl and atomic number 81 It is a silvery-white post-transition metal that is not found free in nature When isolated, thallium resembles tin, but discolors when exposed to air
Thallium: What Are the Symptoms of Poisoning? - MedicineNet Thallium enters the environment primarily from coal-burning and smelting, in which it is a trace contaminant of the raw materials It stays in the air, water, and soil for a long time and is not broken down Some thallium compounds are removed from the atmosphere in rain and snow It's absorbed by plants and enters the food chain