Electrical conductivity. Conductive, insulating, and semiconducting materials

Electrical conductivity at the atomic level

Electrical conductivity depends on the ability of atoms in a material to transfer electrical charges. This property is determined by the atomic structure and, in particular, by the ease with which its electrons can move. Based on this ability, materials are classified as conductors, insulators, or semiconductors, reflecting their ability to allow or impede the flow of electrical charge.

Conductive materials. Metals

Metals are good conductors because of their atomic structure. Metal atoms have free electrons in their outer shell that can easily move between atoms. When an electric field is applied, these free electrons move in the direction of the electric field and carry electric charge. Therefore, metals are good conductors of electricity.

Non-conductive materials. Insulators

Insulators, on the other hand, have a different atomic structure. The atoms in insulators do not have free electrons in their outer shell. Instead, the outer shell electrons are tightly bound to the atoms, making it difficult for them to move. Therefore, insulators cannot carry electric charges and are poor conductors.

Semiconductors

Semiconductors have an atomic structure intermediate between conductors and insulators. They have some free electrons in their outer shell, but not as many as metals. In addition, electrons can easily jump into the conduction band and become free electrons under certain conditions, such as the application of an electric field or energy absorption. Therefore, semiconductors have an intermediate electrical conductivity.