Arsenic

chemistry · toxic · metalloid · natural

A dangerous element. Arsenic is element number 33 on the periodic table, and it's notorious for being seriously toxic to living things. Even tiny amounts can make people very sick.

Found in nature. Arsenic occurs naturally in many minerals deep in the earth, usually mixed together with sulfur and metals. Sometimes it even forms pure crystals that look metallic and shiny.

Related to phosphorus. Arsenic belongs to a group called the pnictogens, which means it shares a lot of properties with elements like phosphorus and antimony, its neighbors on the periodic table.

Gray is the star. Arsenic has different forms called allotropes, but only the gray version with a metallic shine is really important to industry and how we use it.