Sähköjohtavuusominaisuudet

Sähköjohtavuus refers to the ability of a material to conduct electric current. It is the reciprocal of electrical resistivity, which measures how strongly a material opposes the flow of electric current. Materials with high electrical conductivity allow electric charge to flow easily, while materials with low conductivity impede the flow of charge.

In conductors, such as metals, electricity flows readily due to the presence of free electrons that can move throughout the material. These free electrons are not bound to individual atoms and can be easily influenced by an electric field. Common examples of good conductors include copper, silver, and gold.

Insulators, on the other hand, have very low electrical conductivity. In these materials, electrons are tightly bound to their atoms, and there are very few free electrons available to carry an electric current. Examples of insulators include rubber, glass, and plastic.

Semiconductors fall between conductors and insulators. Their conductivity can be controlled by external factors like temperature or the addition of impurities (doping). This property makes semiconductors essential components in electronic devices such as transistors and diodes.

The unit of electrical conductivity in the International System of Units (SI) is siemens per meter (S/m). A higher siemens per meter value indicates better conductivity. Temperature also plays a significant role in conductivity; for most conductors, conductivity decreases as temperature increases due to increased atomic vibrations hindering electron flow.