| Formula / Notation | Se |
|---|---|
| CAS Number | 7782-49-2 |
| Molecular Weight | 78.96 |
| Melting Point | 221.0 |
| Boiling Point | 685.0 |
| Density | 4.82 |
| Solubility | Slightly soluble in water |
| Appearance | Grey metallic solid (most stable) or red amorphous powder |
| Also Known As | Se, selenium element |
| Category | Elements |
What is Selenium?
Selenium is a non-metal/metalloid, atomic number 34. An essential trace element for humans and many other organisms (component of selenoproteins, glutathione peroxidase). Has both metallic and non-metallic forms. Shows photoconductivity - resistance decreases on exposure to light.
Formula & Notation
IUPAC Name: Selenium
Other Names / Synonyms: Se, selenium element
Properties & Characteristics
Physical Data
| Property | Value |
|---|---|
| Melting Point | 221.0 |
| Boiling Point | 685.0 |
| Density | 4.82 |
| Molecular Weight | 78.96 |
| Solubility | Slightly soluble in water |
| Appearance | Grey metallic solid (most stable) or red amorphous powder |
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Selenium is a non-metal/metalloid, atomic number 34. An essential trace element for humans and many other organisms (component of selenoproteins, glutathione peroxidase). Has both metallic and non-metallic forms. Shows photoconductivity - resistance decreases on exposure to light.
Glass decolourant and red colourant. Selenium rectifiers and photocells (historical). Xerography and photocopiers. Dietary supplement (essential trace element). Rubber vulcanisation additive. Anti-dandruff shampoos (selenium sulfide). Solar cells (CIS, CIGS).
Selenium and compounds: toxic - IDLH 1 mg/m3. Hydrogen selenide (H2Se): extremely toxic gas. Chronic selenium poisoning (selenosis): hair loss, nail changes, neurological effects at doses above 400 ug/day. Selenium dioxide: corrosive. Essential but toxic window is narrow.
The formula or notation for Selenium is: Se