Nov 02, 2008 · Sulfur => Insulator (non-metal) Phosphorous => Insulator (non-metal) Germanium => Semiconductor (semiconductor) Conduction depends on the width of the band gap between the valence band and conduction band for elements. For insulators the band gap is so large that it takes a lot of energy for the electrons to jump from one gap to the next. Electricity - Electricity - Conductors, insulators, and semiconductors: Materials are classified as conductors, insulators, or semiconductors according to their electric conductivity. The classifications can be understood in atomic terms. •Insulators: Low Conductivity •Semiconductors: Conductivity can be varied by several orders of magnitude. •It is the ability to control conductivity that make semiconductors useful as “current/voltage control elements”. “Current/Voltage control” is the key to switches (digital logic including microprocessors etc…), Sep 26, 2019 · We typically call an insulator a semiconductor if its band gap (E gap) is less than about 3 eV. A semimetal is a material that has a band gap near zero, examples being single sheets of sp 2-bonded carbon (graphene) and elemental Bi. Like a narrow gap semiconductor, a semimetal has higher conductivity at higher temperature. Back to top Tutorial on Chemical Bonding, Part 10 of 10 (Metals and semiconductors) The most useful treatment of metallic solids is based on the molecular orbital approach.. It is best understood by considering first a succession of molecules based on lithium (or any other alkali metal having a single s electron in its valence shell).