Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250. Arsenic is a metalloid. It can exist in various allotropes, although only the gray form has important use in industry.Symbol: As
Atomic number: 33
Electron configuration: [Ar] 4s2 3d10 4p3
Melting point: 2500 BC
Atomic mass: 74.9216 ± 0.00002 u
Discoverer: Albertus Magnus