Thallium
Thallium, with the chemical symbol Tl and atomic number 81, is a fascinating yet notorious element. Discovered in 1861 by the English chemist Sir William Crookes, its name is derived from the Greek word "thallos," meaning "green," due to the green spectral lines it produces. While relatively rare on Earth, constituting only about 0.5 ppm of the Earth's crust, thallium has found some intriguing applications.
Historically, thallium compounds were used in rodent control and agriculture, but due to their toxicity, these applications are obsolete today. In medicine, thallium is utilized in nuclear medicine studies, particularly in cardiac diagnostics.
The production of thallium involves mining ores, mainly in China and Australia, followed by complex chemical processes for purification and isolation. The main production countries play a significant role in global thallium production.