Physics – 2.3.1 Conduction | e-Consult

The electrical conductivity of a metal is directly proportional to the number of free electrons present. More free electrons mean a greater ability for the metal to conduct electricity. This is because a higher concentration of free electrons provides more charge carriers to contribute to the electric current when a potential difference is applied.

Different metals have different numbers of free electrons due to their atomic structure and the number of valence electrons available for delocalisation. Metals with fewer valence electrons or those where the electrons are more tightly bound to the atoms will have fewer free electrons and therefore lower conductivity. For example, copper and silver have a high number of free electrons and are excellent conductors, while materials like insulators (e.g., rubber, glass) have very few free electrons and are poor conductors. The ease with which electrons can move through the metal lattice also plays a role; metals with a more regular and less disrupted lattice structure generally exhibit higher conductivity.