Arsenic (As)

Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal.

Atomic Number

33

Atomic Mass

74.922 u

Category

metalloid

Phase

solid

Density

5.727 g/cm³

Electron Shells

2, 8, 18, 5

Atomic Structure

Protons: 33 • Electrons: 33 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³

Discovery

Unknown