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Materials with Lots of Free Electrons are Called
By BYJU'S Exam Prep
Updated on: September 25th, 2023
Materials with lots of free electrons are called-
- Conductors
- Insulators
- Semiconductors
- Dielectrics
Table of content
Answer: A. Conductors
Materials with lots of free electrons are called conductors.
Solution
Valence Band (VB): The band created by a sequence of energy levels containing valence electrons is referred to as the valence band.
Conduction Band (CB): The next higher permitted energy band is called the conduction band. It may also be defined as the lowest unfilled permitted energy band. It may be empty or partially filled with electrons. The electrons can move freely in the conduction band; hence, the electrons in the conduction band are called conduction electrons.
Conductors: Conductors are having lots of free electrons on the conduction band. The energy gap between the valence and conduction band is zero.
Insulators: In insulators, the valence (outer) electrons are tightly held together. When the movement of electrons is restricted, no current can flow. The energy gap between the valence and conduction band is greater than 9 eV.
Semiconductors: Semiconductor acts like an insulator at 0K and conductor at high temperatures. In semiconductors, there is a small energy gap of about 1 eV between the valence band and conduction band.
Dielectrics: The dielectric material is placed in an electric field, electric charge does not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation.
Hence, materials with lots of free electrons are called conductors.
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