Symbol: Tl

Atomic Number: 81

Atomic Weight: 204.3833

Thallium (atomic number 81, symbol TI) is a post-transition metal and chemical element that was discovered in 1861 by Claude-Auguste Lamy and William Crookes. They discovered the element independently by using a new method known as flame spectroscopy. This is a method used to study the composition of chemicals and minerals.

Chemical and Physical Properties
Thallium is a lustrous, sectile, malleable, and soft metal that tarnishes when reacting with air. Nitrate and sulfate salts are formed when thallium reacts with nitric acid and sulfuric acid. The element has 25 isotopes and TI-205 and TI-203 are stable. This metal has a hexagonal...Read More