1 For a 2-hour party, Cork Catering in Illinois charges $7.50 per guest for beer or wine only and $14.50 per guest for a premium bar serving most types of mixed drinks. 2  For detailed open bar pricing, see How Much Does an Open Bar Cost. For a 2-hour party, Cork Catering in Illinois charges $7.50 per guest for beer or wine only and $14.50 per guest for a premium bar serving most types of mixed drinks. 2  For detailed open bar pricing, see How Much Does an Open Bar Cost.
Selenium exists in a number of allotropic forms. Allotropes are forms of an element with different physical and chemical properties. One allotrope of selenium is an amorphous red powder. A lump of clay is an example of an amorphous material. A second allotrope of selenium has a bluish, metallic appearance.
Selenium is a component of metal alloys, where it improves machinability of the final material and often replaces the more toxic metal lead. Though excessive quantities of selenium can be toxic, the element is also an important micronutrient, as it is a necessary cofactor for several enzymes.