Selenium
MATERIAL OVERVIEW
Characteristics: 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.
Crystalline selenium is a p-type semiconductor and electrically, it acts as a rectifier, and has marked photoconductive and photovoltaic action (converts radiant to electrical energy). The electrical conductivity increases with increasing light irradiation.
Soluble in concentrated nitric acid and in (liquid form) common alkalies. Forms binary alloys with silver, copper, zinc, lead, etc. Low toxicity. A necessary nutritional factor for animals.
Hazards: Selenium salts are toxic in large amounts, but trace amounts are necessary for cellular function.
To view a photo of the item hover over the icon.
GENERAL PROPERTIES
Symbol: |
Se |
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 |
TYPICAL ANALYSES - Impurities in ppm
Material / Purity: |
5N |
As | <1 |
Cu | <1 |
Te | <1 |
SELENIUM POWDER, SHOT, PELLETS, & INGOT
Material |
Purity |
Selenium Shot 1-3mm or 1-5mm | 5N |
Selenium Pieces 5mm and Down | 5N |
Selenium Powder-200 Mesh | 2N7 |
Selenium Powder-325 Mesh | 2N7 |
Powder, shot, pellets, and ingots are packaged to order and sold by the gram or kilogram. Call or This email address is being protected from spambots. You need JavaScript enabled to view it. for additional specifications or custom requirements.
|
|