Arsenic

Arsenic

Arsenic is a chemical element; it has the symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is notoriously toxic. It occurs naturally in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. It has various allotropes, but only the grey form, which has a metallic appearance, is important to industry.

arsenic

Noun

1. A toxic grey brittle nonmetallic chemical element (symbol As) with an atomic number of 33.
2. A single atom of this element.

Adjective

1. Of or containing arsenic with a valence of 5.