Amorphous red powder, becoming black on standing and crystalline on heating; vitreous and colloidal forms may be prepared.
Amorphous form softens at 40 °C and melts at 217 °C. It rarely occurs in its elemental state in nature, or as pure ore compounds.
Symbol:
|
Se
|
CAS
|
7782-49-2
|
Atomic Number:
|
34
|
Atomic Weight:
|
78.96
|
Density:
|
4.79 gm/cc
|
Melting Point:
|
217 oC
|
Boiling Point:
|
684.9 oC
|
Thermal Conductivity:
|
0.00519 W/cm/K @ 298.2 K
|
Electrical Resistivity:
|
106 microhm-cm @ 0 oC
|
Electronegativity:
|
2.4 Paulings
|
Specific Heat:
|
0.767 Cal/g/K @ 25 oC
|
Heat of Vaporization:
|
3.34 K-cal/gm atom at 684.9 oC
|
Heat of Fusion:
|
1.22 Cal/gm mole
|
Brand
|
Epoch-Chem
|
1 Manufacturing:selenium(I) chlorid,Selenium dichloride,Selenides, mercury selenide.
2 Science high technology industry:lead selenide,zinc selenide, copper indium gallium diselenide.
3 Electric:semiconductors,electropositive metals,Tetraselenium tetranitride.
4 Chemistry:Selenols,selenium isotope,Plastics, photographic exposure.
5 Industry application:Glass making,selenium drum, electrostatic photograph,optical instrument.