Physics materials?

The electrical conductivity of materials is influenced by various factors. Here are some examples:

• Metals: Metals generally have a high electrical conductivity since they have free electrons in their lattice structure which can easily migrate from one atom to another. The electrical conductivity of metals can be increased by increasing the temperature or by alloying with other metals.
• Vacuum: There are no atoms or molecules in a vacuum that can impair the movement of charge carriers. A vacuum therefore has a very high electrical conductivity.
• Semiconductors have a moderately high electrical conductivity since they have a limited number of free electrons. The electrical conductivity of semiconductors can be increased by adding “doping elements” which introduce more free electrons or holes into the material.
• Isolators: insulators generally have a very low electrical conductivity, since they have no or only very few free electrons. Examples of insulators are in particular organic polymers, rubber and ceramics.
• Gases: Gases generally have a low electrical conductivity since they do not have a solid lattice structure and therefore have no free electrons available which can easily migrate from one atom to the other. However, the electrical conductivity of gases can be increased by increasing the density or increasing the temperature.
• Acid, base, salts: acids, bases and salts generally have a low electrical conductivity. The electrical conductivity of acid-base and salt solutions can be increased by increasing the concentration, since this gives more free ions in the solvent, which can easily migrate from one atom to the other.