Thallium (Tl) is a chemical element belonging to the category Post-transition metal, with atomic number 81 and atomic mass 204.3800 u. This sheet describes its fundamental properties, periodic position and physical characteristics.
Identity
- Name: Thallium
- Symbol: Tl
- Atomic number: 81
- Atomic mass: 204.3800 u
Position in the periodic table
- Group: 13
- Period: 6
- Category: Post-transition metal
Physico-chemical properties
- Standard state: Solid
- Melting point: About 304°C
- Density (at 20°C): 11.8 g/cm³
- Electron configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹
Scientific description
Thallium is a chemical element with symbol Tl and atomic number 81. It belongs to the category of Post-transition metal and occupies group 13 and period 6. Its standard atomic mass is 204.3800 u.