|
Thallium |
---|
Pronunciation | (THAL-ee-əm) |
---|
Appearance | sillery white |
---|
Standard atomic weight Ar, std(Tl) | [7002204382000000000♠204.382, 7002204385000000000♠204.385] conventional: 7002204380000000000♠204.38 |
---|
Thallium in the periodic cairt |
---|
|
Atomic nummer (Z) | 81 |
---|
Group | group 13 (boron group) |
---|
Period | period 6 |
---|
Block | p-block |
---|
Element category | Post-transeetion metal |
---|
Electron confeeguration | [Xe] 4f14 5d10 6s2 6p1 |
---|
Electrons per shell | 2, 8, 18, 32, 18, 3 |
---|
Pheesical properties |
---|
Phase at STP | solit |
---|
Meltin pynt | 577 K (304 °C, 579 °F) |
---|
Bylin pynt | 1746 K (1473 °C, 2683 °F) |
---|
Density (near r.t.) | 11.85 g/cm3 |
---|
when liquid (at m.p.) | 11.22 g/cm3 |
---|
Heat o fusion | 4.14 kJ/mol |
---|
Heat o vapourisation | 165 kJ/mol |
---|
Molar heat capacity | 26.32 J/(mol·K) |
---|
Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
882 |
977 |
1097 |
1252 |
1461 |
1758 |
|
Atomic properties |
---|
Oxidation states | −5,[1] −2, −1, +1, +2, +3 (a mildly basic oxide) |
---|
Electronegativity | Pauling scale: 1.62 |
---|
Atomic radius | empirical: 170 pm |
---|
Covalent radius | 145±7 pm |
---|
Van der Waals radius | 196 pm |
---|
Spectral lines o thallium |
Ither properties |
---|
Naitural occurrence | primordial |
---|
Creestal structur | hexagonal close-packed (hcp) |
---|
Speed o soond thin rod | 818 m/s (at 20 °C) |
---|
Thermal expansion | 29.9 µm/(m·K) (at 25 °C) |
---|
Thermal conductivity | 46.1 W/(m·K) |
---|
Electrical resistivity | 0.18 µ Ω·m (at 20 °C) |
---|
Magnetic orderin | diamagnetic[2] |
---|
Young's modulus | 8 GPa |
---|
Shear modulus | 2.8 GPa |
---|
Bulk modulus | 43 GPa |
---|
Poisson ratio | 0.45 |
---|
Mohs haurdness | 1.2 |
---|
Brinell haurdness | 26.4 MPa |
---|
CAS Nummer | 7440-28-0 |
---|
History |
---|
Diskivery | William Crookes (1861) |
---|
First isolation | Claude-Auguste Lamy (1862) |
---|
Main isotopes o thallium |
---|
Isotope |
Abundance |
Hauf-life (t1/2) |
Decay mode |
Product |
203Tl |
29.524% |
- |
(α) |
199Au |
204Tl |
syn |
3.78 y |
β− |
204Pb |
ε |
204Hg |
205Tl |
70.476% |
- |
(α) |
201Au |
|
Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |