Question

Explain how the electron-sea model accounts for the high electrical and thermal conductivity of metals.

Short answer

The electron-sea model, also known as the free electron model, explains the high electrical and thermal conductivity of metals by attributing it to the presence and mobility of delocalized electrons in a "sea" of free electrons within the metal lattice. The high electrical conductivity is a result of free electrons moving under the influence of an applied electric field, carrying an electric current. The high thermal conductivity is due to the rapid movement of free electrons throughout the metal lattice, transferring energy to other electrons and atoms, efficiently conducting heat.

Step-by-step solution

Understand the electron-sea model

The electron-sea model, also known as the free electron model, is a simple and widely used model in solid-state physics to explain the behavior of electrons in metals. In this model, it is assumed that the valence electrons of metal atoms become delocalized and form a "sea" of free electrons. These free electrons move in a continuous medium of positively charged metal ions.

Electrical conductivity in metals

The high electrical conductivity of metals can be explained by the electron-sea model in the following way: When a voltage is applied across a metal, it creates an electric field inside the metal. This electric field exerts a force on the free electrons present in the electron sea, causing them to move in the direction opposite to the electric field (since electrons are negatively charged). As the free electrons move, they carry an electric current. Since there are a large number of free electrons available in metals and they are highly mobile, metals have high electrical conductivity.

Thermal conductivity in metals

The high thermal conductivity of metals can also be attributed to the electron-sea model. When heat is applied to a metal, the atoms and free electrons gain kinetic energy. The free electrons, being highly mobile, can quickly move throughout the metal lattice, transferring energy to other electrons and atoms. This rapid movement of electrons allows metals to efficiently conduct heat. Furthermore, the electron motion also contributes to the energy transfer and lattice vibrations, which helps to dissipate heat quickly, leading to high thermal conductivity in metals. In conclusion, the electron-sea model provides a straightforward and intuitive explanation for the high electrical and thermal conductivity of metals, as it highlights the presence and mobility of free electrons in the metal lattice.