Tl

Tl, also known as thallium, is a chemical element with the symbol Tl and atomic number 81. It is a soft, malleable, and highly toxic metal that is classified as a post-transition metal. Thallium is notable for its use in certain low-temperature thermometers and in the production of infrared detectors. It is also used in the manufacture of electronic components and in the glass industry.

Thallium was discovered in 1861 by William Crookes. It is typically found in trace amounts in various minerals, including sphalerite and crookesite. The primary source of thallium is the mineral crookesite, which is primarily found in Bolivia. Thallium is extracted through a process involving roasting and leaching.

Thallium has several isotopes, with the most stable being thallium-203 and thallium-205. Thallium-204 is the only stable isotope, and it is the most abundant. Thallium-204 has a half-life of approximately 3.78 years and decays into lead-204.

Thallium is highly toxic and can cause severe health issues if ingested or inhaled. It can accumulate in the body and affect the nervous system, leading to symptoms such as nausea, vomiting, and in severe cases, coma and death. Due to its toxicity, thallium is regulated and its use is closely monitored.

Thallium's unique properties make it valuable in certain applications, but its toxicity necessitates careful handling and disposal. Its use is primarily limited to specialized industrial and scientific applications, and its production and use are subject to strict regulations to ensure safety.