Selenium Pellet (Evaporation Material) - Se

Selenium is a non metallic chemical element, member of the group VI. In chemical activity and physical properties it resembles sulfur and tellurium.The steady selenium are a red amorphous  crystalline powder, and a gray crystalline metallike form called metallic selenium. Metallic  selenium form conducts electricity better in the light than in the dark and is used in photocells. Selenium burns in air and is uneffected by water, but dissolves in concentrated nitric acid and alkalis.