81Tl
Thallium
Post-transition metal
Properties of Thallium
- Atomic number (Z)
- 81
- Symbol
- Tl
- Name
- Thallium
- Atomic mass
- 204.383 u
- Period
- 6
- Group
- 13
- Family
- Boron group
- Classification
- Post-transition metal
- Electron configuration
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹
About Thallium
Thallium is a chemical element with symbol Tl and atomic number 81 (atomic mass of about 204.383 u). It is classified as a post-transition metal on the periodic table.
On the periodic table, Thallium is located in period 6, in group 13, belonging to the boron group family. An element's position reveals trends in its properties, such as atomic radius, electronegativity and metallic character.
The electron configuration of Thallium is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹, which determines how it forms chemical bonds and takes part in reactions.