Metalloids, or semi-metals, are a group of elements that possess both properties of metals and non-metals.
The following six elements are commonly regarded as metalloids:
Metaloids are brittle, lustrous metallic elements that exhibit semiconductive properties.
Being too brittle and weak for structural applications, metalloids are most often used in the chemical, electronics and alloy industries.
Germanium and silicon were critical in the development of the first transistors in the late 1940s and are, to this day, an integral part of semiconductors and solid state electronics.
Metallic antimony is widely used in alloys such as pewter and Babbitt, while chemical forms of antimony are used as a flame retardant ingredient in plastics and other materials.
Tellurium is used as an alloying agent to improve the machinability of certain steels, as well as in electro-thermal and photovoltaic applications due to its unique thermal conductivity properties.
Also used as a dopant in some semiconductors, arsenic is more often found in metal alloys with copper and lead where it acts as a strengthening agent.
The terms 'metalloid' comes from the Latin metallum, meaning metal, and oeides, meaning 'resembling in form and appearance'.