As a materials science expert with a background in physics, I can provide a comprehensive explanation of why metals are good conductors of electricity while glass is not. The key to understanding this lies in the atomic structure and the behavior of electrons within these materials.

Metals are known for their excellent electrical conductivity, which is largely due to the presence of free electrons. These free electrons are not tightly bound to any particular atom and can move freely throughout the metal lattice. This mobility is a result of the way metals are bonded. In metals, atoms are bonded together by metallic bonds, which are formed by the sharing of free electrons across a lattice of positive ions. This delocalized electron cloud allows the electrons to move easily when an electric field is applied, facilitating the flow of electric current.

The valence electrons of a metal atom are in an energy band that extends across the entire solid. This band is known as the conduction band. In metals, the valence and conduction bands overlap or are very close, which means that electrons can easily transition from the valence band to the conduction band. This overlap allows for a high density of mobile charge carriers, which are essential for electrical conductivity.

On the other hand, glass is an example of an insulator. The atomic structure of glass is quite different from that of metals. Glass is typically made from silicate materials, which are composed of silicon and oxygen atoms bonded together in a network structure. In this structure, each silicon atom is covalently bonded to four oxygen atoms, and each oxygen atom is covalently bonded to two silicon atoms. This forms a continuous network with no free electrons available to carry an electric charge.

The electrons in glass are localized within the covalent bonds and are not free to move around as they are in metals. The energy levels of these electrons are in a valence band, and there is a significant energy gap, known as the band gap, between the valence band and the next higher energy level, which would be the conduction band if it were present. In insulators like glass, this band gap is large enough that electrons cannot easily gain the energy needed to jump from the valence band to the conduction band. Without a conduction band or free electrons, there is no mechanism for the flow of electric current, and thus glass does not conduct electricity.

Moreover, even if there were some electrons that could move, the network structure of glass would impede their movement. The rigid and continuous nature of the silicate network means that any electrons that might be able to move would have to overcome significant barriers to do so, making the conduction of electricity in glass extremely inefficient.

In summary, the difference in electrical conductivity between metals and glass can be attributed to the presence of free electrons in metals and the absence of such electrons in glass, along with the differences in their atomic and electronic structures. Metals have a conduction band that allows for the free movement of electrons, while glass has a rigid network structure with a large band gap that prevents the movement of electrons.

read more >>

Glass is not a goodthermal conductor as metals are. But it is a good thermal insulator. Metals are good conductor of electricity and glass in not because in metals electrons are free to move but in glass there is no mobile of free electrons so glass doesnot conduct electricity .Mar 16, 2018read more >>