Thallium is a soft, highly toxic metal used only in controlled electronics, optical materials, and scientific applications.
Atomic number
81
Category
Post-transition metal
Period
6
Group
13
State
Solid
Fun facts about Thallium
Thallium compounds can mimic potassium in biological systems.
Its salts were once used as poisons but are now tightly restricted in many places.
Thallium-doped crystals can detect ionising radiation.
Common uses of Thallium
Radiation detector crystals
Infrared optical materials
Scientific research
Where Thallium sits in the periodic table
Thallium is classified as a post-transition metal in period 6 and group 13 of the periodic table. Under the conditions represented in this reference, its state is solid.
Quick chemistry revision
For quick revision, pair the symbol Tl with atomic number 81 and the listed atomic mass 204.38. The summary, facts, and uses above keep those element properties together in one reference.