Thallium (Tl) — Post-transition metal. Atomic number 81.
Soft gray metal
- Atomic number: 81
- Symbol: Tl
- Atomic mass: 204.38 u
- Category: Post-transition metal
- State: Solid
- Melting point: 303.85 °C / 577 K
- Boiling point: 1472.85 °C / 1746 K
- Density: 11.85 g/cm³ (20°C)
- Electron configuration: [Xe] 4f14 5d10 6s2 6p1
- Oxidation states: +1, +3
- Electronegativity: 1.62
- Discovered by: William Crookes (1861)
Common uses: Electronics, Infrared detectors, Glass
Biological role: No biological role.
Frequently Asked Questions about Thallium
What is the atomic number of thallium?
Thallium has an atomic number of 81, meaning each atom contains 81 protons in its nucleus.
What is the atomic mass of thallium?
The standard atomic weight of thallium is 204.38 u (unified atomic mass units).
What category does thallium belong to?
Thallium is classified as a post-transition metal.
What is the state of thallium at room temperature?
Thallium is a solid at 20 °C (68 °F).
What is the melting point of thallium?
The melting point of thallium is 303.85 °C / 577 K.
What is the boiling point of thallium?
The boiling point of thallium is 1472.85 °C / 1746 K.
What is the density of thallium?
The density of thallium is 11.85 g/cm³ (20°C).
What is the electronegativity of thallium?
Thallium has a Pauling electronegativity of 1.62.
What is the electron configuration of thallium?
The electron configuration of thallium is [Xe] 4f14 5d10 6s2 6p1.
What are the common oxidation states of thallium?
Thallium commonly exhibits the following oxidation states: +1, +3.
When was thallium discovered?
Thallium was discovered in 1861 by William Crookes.
Is thallium radioactive?
Thallium is a stable element with no naturally occurring radioactive isotopes.
What is the biological role of thallium?
No biological role.
What are the common uses of thallium?
Thallium is used for: Electronics; Infrared detectors; Glass.
