Astatine
Astatine, 85At
| General properties |
| Name, symbol
|
astatine, At |
| Pronunciation |
or
AS-tə-teen or AS-tə-tin
|
| Appearance |
unknown, probably metallic |
|
| Astatine in the periodic table
|
|
|
| Atomic number (Z) |
85 |
|
Group, block
|
group 17 (halogens), p-block
|
| Period |
period 6 |
| Element category |
metalloid, sometimes classified as a nonmetal, or a metal
|
|
Standard atomic weight (Ar)
|
(210) |
| Electron configuration |
[Xe] 4f14 5d10 6s2 6p5
|
|
per shell
|
2, 8, 18, 32, 18, 7 |
| Physical properties |
| Phase |
solid |
| Melting point |
575 K (302 °C, 576 °F) |
| Boiling point |
610 K (337 °C, 639 °F) |
|
Density near r.t.
|
(At2) 6.35±0.15 g/cm3(predicted)
|
| Molar volume |
(At2) 32.94 cm3/mol (predicted)
|
| Heat of vaporization |
(At2) 54.39 kJ/mol |
|
Vapor pressure
|
