Atomic Properties
- Atomic Number
- 81
- Atomic Mass
- 204.3800 u
- Electron Configuration
- [Xe] 4f14 5d10 6s2 6p1
- Electronegativity
- 1.62
- Block
- p-block
- Group
- 13
- Period
- 6
Physical Properties
- Phase (STP)
- solid
- Melting Point
- 577.00 K
- Boiling Point
- 1746.00 K
- Density
- 11.8500 g/cm³
About Thallium
Highly toxic; historically used as rat poison; used in electronics.
Isotopes of Thallium
Thallium has 2 naturally occurring isotopes.
| Isotope | Mass Number | Atomic Mass (u) | Abundance | Type |
|---|---|---|---|---|
| 203Tl | 203 | 202.9723446 | 29.52% | Stable |
| 205Tl | 205 | 204.9744278 | 70.48% | Stable |
Data source: NIH PubChem (aggregated from IUPAC, NIST)