81 Tl
Post-transition metal
Thallium
Highly toxic.
Properties of Thallium
- Atomic number (Z)
- 81
- Symbol
- Tl
- Atomic mass
- 204.38 g/mol
- Category
- Post-transition metal
- Group
- 13
- Period
- 6
- Electron configuration
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹
- Electronegativity (Pauling)
- 1.62
- Atomic radius
- 156 pm
- First ionization energy
- 589 kJ/mol
- Melting point
- 577 K (303.9 °C)
- Boiling point
- 1746 K (1472.8 °C)
- Density
- 11.85 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1861
Frequently asked questions
What is Thallium?
Thallium (Tl) is a post-transition metal, element number 81 on the periodic table. Highly toxic.
What is the atomic number and atomic mass of Thallium?
Thallium has atomic number 81 and an atomic mass of about 204.38 g/mol.
What is the electron configuration of Thallium?
The electron configuration of Thallium is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹.
Where is Thallium on the periodic table?
Thallium sits in group 13, period 6, and is classified as a post-transition metal.