81 · Tl
Thallium
Discovered by Crookes in 1861.
Identity
- Atomic number
- 81
- Symbol
- Tl
- Canonical name
- Thallium
- Category
- post-transition metal
- Group
- 13
- Period
- 6
- Block
- p
Properties
These quantities come from the Periodic Table JSON compilation. They have not yet been checked, one by one, against CIAAW atomic weights or NIST measurements. A value marked estimated is not a measurement.
- Atomic mass
- 204.38 u
- Electron configuration
- [Xe] 4f14 5d10 6s2 6p1
- Electrons per shell
- 2, 8, 18, 32, 18, 3
- Standard state
- solid
- Density
- 11.85 g/cm³
- Melting point
- 577 K
- Boiling point
- 1,746 K
- Electronegativity
- 1.62 Pauling
- First ionization energy
- 589.4 kJ/mol
- Electron affinity
- 36.4 kJ/mol
History
A green line
Discovery · confirmed · 1861
Crookes discovers thallium by spectroscopy in lead-chamber mud.
Etymology
- Theme
- color
- Language
- grec
- Root
- thallos
- Meaning
- green shoot
Scientists
Places and institutions
- London — historical setting : United Kingdom — present country : United Kingdom
See also
Sources
- IUPAC, Periodic Table of the Elements
- Bowserinator, Periodic Table JSON. Compilation secondaire d’où viennent les grandeurs physiques importées (masse, densité, températures, énergies). Elles ne sont pas revérifiées une à une auprès du NIST ou de la CIAAW.
- John Emsley, Nature’s Building Blocks: An A–Z Guide to the Elements