Science, Tech, Math › Science 10 Examples of Electrical Conductors and Insulators Things That Don't Conduct Electricity and Things That Do Share Flipboard Email Print ThoughtCo. Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated November 24, 2019 What makes a material a conductor or an insulator? Simply put, electrical conductors are materials that conduct electricity and insulators are materials that do not. Whether a substance conducts electricity is determined by how easily electrons move through it. Electrical conductivity is dependent on electron movement because protons and neutrons don't move—they are bound to other protons and neutrons in atomic nuclei. Conductors Vs. Insulators Valence electrons are like outer planets orbiting a star. They're attracted enough to their atoms to stay in position but it doesn't always take a lot of energy to knock them out of place—these electrons easily carry electric currents. Inorganic substances like metals and plasmas that readily lose and gain electrons top the list of conductors. Organic molecules are mostly insulators because they're held together by covalent (shared electron) bonds and because hydrogen bonding helps stabilize many molecules. Most materials are neither good conductors nor good insulators but somewhere in the middle. These don't readily conduct but if enough energy is supplied, the electrons will move. Some materials in pure form are insulators but will conduct if they are doped with small quantities of another element or if they contain impurities. For example, most ceramics are excellent insulators but if you dope them, you can create a superconductor. Pure water is an insulator, dirty water conducts weakly, and saltwater—with its free-floating ions—conducts well. 10 Electrical Conductors The best electrical conductor, under conditions of ordinary temperature and pressure, is the metallic element silver. Silver is not always an ideal choice as a material, however, because it is expensive and susceptible to tarnishing, and the oxide layer known as tarnish is not conductive. Similarly, rust, verdigris, and other oxide layers reduce conductivity even in the strongest conductors. The most effective electrical conductors are: SilverGoldCopperAluminumMercurySteelIronSeawaterConcreteMercury Other strong conductors include: PlatinumBrassBronzeGraphiteDirty waterLemon juice 10 Electrical Insulators Electric charges do not flow freely through insulators. This is an ideal quality in many cases—strong insulators are often used to coat or provide a barrier between conductors to keep electric currents under control. This can be seen in rubber-coated wires and cables. The most effective electrical insulators are: RubberGlassPure waterOilAirDiamondDry woodDry cottonPlasticAsphalt Other strong insulators include: FiberglassDry paperPorcelainCeramicsQuartz Other Factors That Influence Conductivity The shape and size of a material affect its conductivity. For example, a thick piece of matter will conduct better than a thin piece of the same size and length. If you have two pieces of a material of the same thickness but one is shorter than the other, the shorter one will conduct better because the shorter piece has less resistance, in much the same way that it's easier to force water through a short pipe than a long one. Temperature also affects conductivity. As temperature increases, atoms and their electrons gain energy. Some insulators like glass are poor conductors when cool but good conductors when hot; most metals are better conductors when cool and less efficient conductors when hot. Some good conductors become superconductors at extremely low temperatures. Sometimes conduction itself changes the temperature of a material. Electrons flow through conductors without damaging the atoms or causing wear. Moving electrons do experience resistance, though. Because of this, the flow of electrical currents can heat conductive materials.