Description: Arsenic's name comes from the Greek term for an arsenic compound, orpiment (arsenic trisulfide). Arsenic is a metalloid element, which, like phosphorus, has two main forms. One is a brittle, gray metallic form and the other is a yellow, non-metallic solid.Yellow arsenic is the more reactive and unstable of the pair. Arsenic is stable, being unaffected by air, water, most acids and alkalis.Arsenic has no liquid phase; the solid sublimes directly into a vapor.rsenic has semiconductor properties and is used in making transistors. It is also used in alloys, glass production, pyrotechnics and wood preservatives. An arsenic-gallium compound is used in making lasers.