What Is Selenium?
Selenium, with symbol Se and atomic number 34, is a chalcogenic element that exists in several forms, ranging from a dark reddish-brown amorphous solid to metallic gray crystals. As an essential trace element, selenium plays a crucial role in human health, being part of the enzyme glutathione peroxidase, which has antioxidant properties.
Uses of Selenium
Selenium’s semiconducting and photoconductive properties are harnessed in rectifiers, photocopiers, and photovoltaic cells, though its use is limited by its toxicity. It also serves as a colorant, rubber additive, and dietary supplement, with its bioavailability influenced by soil selenium concentrations.
Properties of Selenium
Selenium displays various allotropes and transforms with temperature changes. It has a melting point of 170-217°C and a boiling point of 685°C. Selenium is commercially available in amorphous and crystalline forms, showing different physical characteristics based on preparation methods.
Other Information on Selenium
1. Selenium Manufacturing Process
Selenium is typically extracted from selenide in sulfide ores through copper refining. The process involves oxidizing selenium dioxide and reducing it to metallic selenium with sulfur dioxide.
2. Selenium Reactions
It reacts with oxygen, fluorine, and cyanide to form various compounds, showcasing its versatility in chemical reactions across different oxidation states.
3. Regulatory Information
Regulated under multiple laws for its poisonous nature and environmental impact, selenium usage requires stringent handling and labeling protocols.
4. Handling and Storage Precautions
Safe handling involves storing in cool, dark places, using protective gear, and avoiding contact with strong acids and oxidizers to mitigate health and safety risks.