Key Concepts and Summary
The elements boron, silicon, germanium, arsenic, antimony, and tellurium separate the metals from the nonmetals in the periodic table. These elements, called metalloids or sometimes semimetals, exhibit properties characteristic of both metals and nonmetals. The structures of these elements are similar in many ways to those of nonmetals, but the elements are electrical semiconductors.
solid material such as a glass that does not have a regular repeating component to its three-dimensional structure; a solid but not a crystal
compound containing boron-oxygen bonds, typically with clusters or chains as a part of the chemical structure
variation in crystalline structure that results in different physical properties for the resulting compound
compound containing silicon-oxygen bonds, with silicate tetrahedra connected in rings, sheets, or three-dimensional networks, depending on the other elements involved in the formation of the compounds